Adam - a few things I would suggest: 1) Your oil reservoir is pretty small, so you have to consider that the amount the oil temperature around your steel is going to increase significantly in the first fraction of a second. I would consider a larger quench with more oil and preheat the oil and stir it ahead to ensure temperature equilibrium to avoid cold spots during quenching; 2) You are carrying your heated steel pretty far in tongs, which is going to act differently than the steel that is exposed to atmosphere directly, not to mention rapidly reduce steel temp and the safety concerns, I would consider changing the location of your oven/quench and use a tong or hook that minimizes surface contact; 3) You appear to be quenching in a plastic or pvc container on concrete - I would seriously suggest switching to a steel container and keep a chemical extinguisher nearby, as oil fires are often combustive and all it takes it for you to bump that container and it will likely melt a hole and then you have a hot oil spill; 4) I would also suggest wearing a filtered mask, not just a face shield, as burning/smoking oils are not so good to breathe, whether in the kitchen or shop.
i completely agree with this comment the heat treat could have been done a lot better and more efficient.. and the whole not enough oil thing is right but at the same time hes not taking .100 thou or anything too aggressive and its not a big piece of material but anymore then that yeah hed be chasing his tail till the part was scrap! dont get me started on the ambient temperature of a machine lmaooo!!!!!!
Great work there, as always. There is a decarburized scale layer on the outside, yes. It will definitely throw off the reading, but its only a few thou thick. The grey spotty texture is martensite. Good sign that the heat treat was successful. For the quench - 40 to 45 is quite ok for a piece that size. Large pieces lose a lot of max HRC due to pretty much annealing while still in the quench due to residual heat in the center. Still, you 're not quite there, yet - 4140 is supposed to harden to 50-60. Your quench technique is fine, but you lost a lot of hardness in the transfer. First - get your oil right next to the oven, or the oven next to the oil if you want to quench outside for smoke reason. The goal is to pretty much open the door and drop it right out of the kiln into the oil in a blink of an eye. If you need more than 2 seconds for a transfer, it's pretty much too late to get a good result, already. Also - get yourself a metal bucket - if the plastic breaks (or you get contact and melt through it), you get a spill of hot, and maybe even burning oil.
Same here. Grew up with my dad taking me into the metal fab shop 3 or 4 times a year, worked there two summers. Still remember the smell of the oil and grease, metal shard hitchhikers in the soles of my boots scraping the concrete or pavement. Great people to work with. Love seeing Abom's work in his vids from a raw forging to perfection.
Hey Adam, not to be overly picky but for more accuracy; when doing the hardness testing with that calibrated spring punch, you should make sure that the test piece is lying on a flat, hard surface. I believe that plastic tray absorbed some of the penetrating force of the punch. When you punched the second sheeve, i thought I saw the tray bow flatten a bit. This will affect the hardness test.
Adam, I'm suspicious that the area of differential hardening may be due to you grabbing the part with cold tongs. When I heat treat (knives and edge tools), I make sure that my tongs are quite hot, almost glowing red themselves.
Seconded, as well as a recommendation for a larger quench tank and more vigorous agitation. With anything that chunky ensuring really good even contact with the oil is huge.
@@thereddufus The tongs being cool wouldn’t be as much of a factor as the size of the quenching tank. The volume of oil and the lack of good convecting flow of the quenching fluid would be the biggest factors in inconsistent cooling rate leading to differing phase change progression and different final phase presence. Thus causing the varying hardness.
i worked in a heat threating company for 5 yrs doing the tests u should allways clean any millscale or any type of residue on ur parts before testing and allso im pretty sure that the "raised discoloured" area is where u had the thongs and it held in more heat than the rest of the part we used #9 steel wire to attach it or and lower it so the part would cool down all at the same time in the quenching liquid
Your idea about scale messing up the readings is correct. I use regular sandpaper to clean the surface before measuring. Make sure that the surface is parallel to the measurement axis, clean surfaces and support workpiece properly. Still you might want to make multiple measurements as the hardness measurement is very sensitive to different variations. Maybe you could acquire a hardness calibration piece to check your measurement. With handheld hardness testers it is a must have as it is easy to start second guessing yourself while measuring. This is why hardness requirement has always a tolerance. I have been using and have seen +2 -2.
Your tongs insulated that part of the steel. And created a Hamon, It cooled at a different rate than the rest of the steel. Use a wire Hanger or Pre heat the tongs and oil.
Pre heating the tongs and oil and keeping the oil close to the oven should give a more even hardness. The uneven results are probably due to the uneven cooling and quench. Had those issues with the first couple of heat treatment cycles I did.
I have no real knowledge of this sheave, however I know that a lot of cable type lift equipment is designed to have the sheave wear, and not the cable. be careful changing the design specs. love the videos Abomb. thanks and keep up the great work.
Yep, I am afraid 45-50 HRC is way too hard for this application. Standard 4140 bar stock is around 12-15 HRC. Probably a better choice. I think the cable would agree!
Adam, here is a thought. You mentioned that one area of the part had a hardness of 62. Could that be the area that was in contact with the tongs used to remove the part from the oven ? The heat transference from the part to the cold tongs may be the reason for the higher Rockwell rating in a small area of the part.
Couple of ideas re quenching your parts: First of 4140 is not the best of materials for this purpose due to low carbon content. It will harden, but do not expect tool steel hardness levels. Secondly, when you heat your parts for long time, decarburization happens in the top layers. Basically you loose carbon from steel thus making top layers softer (regardless of the scale). As others mentioned, keep your oil bath as close to the furnance as possible. I would personally try running some tests with smaller parts and if you want to use 4140 try quenching in water as well. Anyway it was a enjoyable video, good job Abom!
4 года назад+2
4140 is an oilhardening steel as per material specifications. water hardening can lead to cracks in the part. to avid decarbonisation either use an oven with inert gas atmosphere (expensive) or toolwrap (cheaper, but not feasible for all geometries). This steel has .4% carbon which is easily enough for decent hardness while cromium and molybdenum make it less brittle. Exactly what you would want for the purpose of the part decribed, so choice of material is good. Typical application for a tempered steel grade. Very similar to the 41CrMo4 /1.7223 we use over here in Europe for the same kind of applications. There are detailed tables regarding how long it takes to heat through the whole part depending on wall thickness and which temperatures to use as wella s which quenching agent and so on. If you adhere to those you will get good results, otherwise you will not.
When you dip the larger parts to you move it in a circle. If you don't the you will get gas pockets around the part and it will cool slower. On 1040-1060 you can do a saltwater bath. You can always do a magnet test before the quench. This will make sure your at the right temperature to maximize hardness. Love your clips I learn so much from you.
Hey Adam,Directly after you harden the parts at 880°C for a minimum of 1 hour (the longer you leave it in, the deeper the hardened surface will go it is a case harden steel). You need to heat your oil to 360°C, quench and keep the parts at a constant temp for at least 2 hours then cooled to room temp for 4140 1.7225. This is the austemper temperature. You should be getting 61HRC after hardening. The steel is not hardened completely, you can still cut it with a conventional laith. Normally hardened steel to 58+3 HRC needs to be cut with a CBN or diamond insert using HSC. Normally you should grind the parts afterwards, and leave a good 0.6mm extra mass for clean-up. You should also do a magnet powder test to check for cracks.
That high of oil temp is totally unnecessary, depending on your industry and country and code of regulations you follow. We heat treat 4140 all the time and it is quenched in 150F oil, and is supposed to be from 140-180 max.
@@Sffker normally you're supposed to use a heated salt bath (like we do at work). You have 2 possibilities, 1) you austenize (minimum 60 min), quench, then temper in a heated bath 360°C-480°C minimum 2 hours 2)austenize (minimum 60 min), quench, and temper in an oven at 680°C for minimum 2 hours. The data provided is the temperature, specifically for an oil quench and not a salt bath quench. According to my machinist handbook they state 42CrMo4 material number 1.7225 (AISI 4140) harden at 880°C quench in water or oil, temper between 540°C-680°C (lower temp for water quench, higher temp for oil quench). The 4140 hardens through tempering. Hence why Adam doesn't have 58+HRC. Depending on application, the best results come from an oven using nitrogen, quenched in a salt bath, tempered in a salt bath. Up to 61HRC. The raw steel is delivered with a 53HRC.
@@chronicblazer84 Well he showed your last statement to be wrong. His was far less than 53 to start with. I have gotten 4140 steel in both a soft state and a hard state. 24" rod I have chucked in the lathe right now is toward the hard end of the scale. The other chunk I machined recently cut like butter with the same tool. Even just center drilling this new piece told me this one was different hardness to start with. Atlas Steel provides theirs as hardened and tempered. Different sizes also are delivered as different hardness-es. Others may supply theirs as annealed. Or as Atlas says, it can be annealed, machined,and re-heat treated to get to a harder level.
Just recently "discovered" you. You're a natural teacher and craftsman. I'm retired but later in life did precision assembly and machining of smaller parts. I wish I had discovered you when I was doing that work - you would have improved my work!
Thank you for doing videos at this point in time, it's a welcome respite to watch while under COVID-19 house arrest. I especially like the actual machining parts when you make the chips fly!
Try fishing your job out and quenching, using a 1/4” hook. The wide tongs may cause varied quenching spots. Also in Australia we use K-type oil, i think your equal is Parks 50. You need a fast oil.
I know I commented prior to this and I don't mean to beat this to death but I remember probably early seventies we needed to open up a sheave from 3/4" to 7/8" to accept a larger wire rope.. The sheave was out of a Lima crane and it was so hard in the groove that the groove had to be ground to size...Machine shop in Baton Rouge did the job...Cheers; Mike in Louisiana
I have been heat treating similar size parts for a few years now, all 4340. As a guy who has had parts slip out of the tongs, I cringe and hold my breath watching you quench in a plastic bucket. The steel safety cans with the foot operated lid work great.
I enjoy you're showing us your learning in the heat treating. I think the tool you used to hold the part did a much quicker temperature drop so it harder there. That spot you show in the beginning. I didn't see if it is symmetrical, on both faces. Stephan Gottewinter uses steel wire, hooks. I used them too in forge treatment and they work better for me. Thanks for the vid !
Hey ADAM! The differential hardness you noticed may be due to your tongs, and the 'long' walk to the quench. Quench needs to be right next to the furnace, and quick. Practice the moves like you would for a critical weld. Use a metal quench pail with a proper lid. You're on the right track with cross referencing your instrumentation. Can't wait to see you discover case hardening. Make tools from nearly any steel!
@@j-man72b72 right. What little I did in shop and for a hook and shackle company I know the heat to plunge time and orientation is critical. Long parts must go straight in to the oil and maybe letting it drop off the tongs would work better. We also found after quench if the batch was crated and taken outside in a snow storm the hardness went up the Rockwell scale.making them more brittle and lower on the maximum pull strength range. Also Rockwell numbers are not possible to get on round parts of a sample. You need to grind a flat for Rockwell or Brinell
The tongs don't allow the part to cool evenly in the oil quench. Run a piece of wire through the hole in the part before you put in the oven and grab the wire with the tongs to remove it from the oven and quench it. Your quench tank should be metal not plastic. The part can melt a hole in a plastic tank.
That may be the only bit I remember from art school WAY back .... (Fire was the cool new tech). I had a nickel part explode because the tongs were such a great heat sink.
I really like how you are checking and talking about the hardness. I wish you could go see the parts or have them brought back a few years later to see how they held up.
Temper for 90mins bud Your right about the scale affecting test results Your hard spot may have been either the part that hit the oil first or it may have leeched carbon out of your tongs somethings caused an inconsistent quench but nice work all trades in house is the way to go
I'm really looking forward to seeing Adam climb the learning curve and see his heat treating skills improve. It's great watching someone so knowledgeable in something picking up a new skill and seeing that process.
Adam, I love your videos, and I’m very impressed by your attention to details and strive for accuracy. I’m an industrialist at heart and my parents were engineers, so sharing your skills and day to day work activities allows me to live vicariously through you haha Having said all that, I also wanted to suggest that you get a metal bucket or non-meltable container for the quenching oil. The plastic pile is a trouble waiting to happen. Keep up the great work, and the videos coming. Thank you and stay safe.
Usually sheaves that run constantly are hardened in the groove for long life otherwise the wire rope will cut grooves in the sheave and the rope life running over such a groove will be lessened....This is for duty cycle work such as draglines, clamshell machines, magnets, etc where cycle time is two minutes or less .. Rope is constantly running back and forth on these sheaves....Mike in Louisiana
The hard area is where your tongs were when you quenched the part. I recommend you drop the hot part into a heavy wire mesh basket and use an aerator in your quench bucket.
This would make it softer, no? Even on a thick part with all of that heat inside, the tongs will do that? I only know a little bit from making knives, but typically people would feel that the tongs would act as a heat sink if anything, so the part would lose heat faster there and not harden properly. That’s why a lot of people will stick the tongs way into the quenchant just in case, so that the tang isn’t slowed in cooling. It seems extreme to me that tongs could cause a difference of 20 HRC. Maybe I’m that ignorant though, that’s why I’m honestly asking. Maybe this steel is a very slow hardening steel?
the best thing about oil quenching with a plastic bucket is when you touch the side of the bucket and the part blows it out and you have a flaming oil avalanche on your hands. that is, your metaphorical hands. it's on your literal feet. i've been there. also i have no clue why you're getting the results in heat treat that you've been getting, provided everything is calibrated. granted, i rarely bother oil quenching anymore and generally do air or water. but i do know that if you test it without removing the scale it reads high, usually off the scale high, unless it cracks under the force of the diamond, then it's just a random reading edit: watching again, the only thing i do different is hang the parts from stainless safety wire, so it may have been that.
Very informative! But you might want to use a metal pail for your quench oil--if the part slipped out of your pliers it'd melt right through the bottom of a plastic pail, which would be messy even if the oil didn't ignite as the oil level dropped below it...
Hi Adam, great video and explanation. You have skills. We do a lot of machining of various tool steels and we use a prehard NAK55 which is 40-42HRC. It machines excellent and does not need heat treat so you can go right to size after roughing. Its great for polishing, welding, & is very stable.
I’ve learned a lot from your videos in the past, and today I’m learning even more. Homeshop heat treatment of 4140 has always interested me, but I don’t have the equipment (yet). Thank you for taking us with you on this learning curve Adam !
That was what I was thinking too, I'm unsure if the tongs would have cooled it quicker or if they protected it from the quench. I was wondering if it might be better to use a bent rod and hook it through the middle hole.
Hey Adam Started watching your videos about a month ago and I've already seen about 75‰ of them. About 20 years ago I worked at a place called GKN Driveline in Bowling Green, Ohio running CNC milling machines. I really enjoyed it and excelled at it quickly. I had forgotten how much I really loved it until I found your channel and now I'm thinking about getting into it like you. Anyway, love your videos and notice your picture with your Dad and Grandfather at the end of your videos. I would love to hear more about them and how they taught you what you know. Thanks brother. Keep making these awesome videos.
Hi Adam, you might be able to use some TIG Cups to hold your parts up higher when heat treating so that the whole part sits in the same heat layer in the oven.
Just so you know and how this passes on to all I ordered a bag of the lump charcoal from your Amazon store and it is of very high quality to cook with. Not to forget to mention the turn around time from order to delivery is superb. Very excellent to have a place to order that helps perhaps in a small way but does help support the channel!
Leeb (bouncy ball) hardness testers are also a good low cost options for flat surfaces like that. We use a portable digital ultrasonic hardness tester which is a bit more but less than a conventional hardness tester and more versatile.
Abom: puts mat down under bucket of oil in case of mess. The only oil that splashes out of bucket lands on the concrete beside the mat. Ohhhhh Murphy, what would we do without you?
@@gravelydon7072 My father says he doesn't run by Murphy's law. He says that O'Leary's law is more accurate. Apparently O'Leary's law states "Murphy was an optimist".
Adam I'm still figuring out how to contact RUclipsrs real time and this is the closest I could find. I just wanted to tell you how much I envy how you got to learn and work with your Dad and Granddad. I've always liked family businesses, it just seems more American to me! Thanks for all your work and content brother!
At Waner & Swasey they used another type of hardness tester that used a hardened ball bearing. The bearing was dropped in side the gage when the gage rested on the work piece. It measured how high the bearing bounced inside the gage to a scale on the gage . They used it to test the hardness of their bed ways after induction hardening. There seems to be a lot of different types of hardness testers.
If I happen to be away from the shop and have a press fit bearing, I use a can of air duster, available for cheap at Walmart. Turn the can upside down and spray the outer bearing race until it freezes, usually about half a can, then it will drop right in with little or no trouble.
@Abom79 Thanks for educating so many of us RUclipsrs. If it was any kind of automotive part, it would have a snap ring. Cut a groove in the other one. Axial-radial load test.
I’d just toss it in my oven for 20 minutes at 400 degrees, with a bit of BBQ sauce and spicy Cajun seasonings! Don’t forget to cook up a good helping of niblet corn and Mac-and-cheese as sides! 😁
Hi Abom, here's a thought that has just occurred to me. Where you get that hard spot in the workpiece, could it be where you grab it with the tongs? After all they are much colder than the workpiece and would start to cool that point right away, before you reach the quenching oil. Then where the piece is still held by the tongs, could that cause some uneven cooling?
Adam: Two suggestions. Get a metal 5-gallon bucket for your quench. If you touch the side of the plastic bucket with the hot metal you could melt through. Second, move the quench bucket and the furnace closer together. What causes the scale is the oxygen in the atmosphere, even for that minimum few seconds it takes from furnace to quench. Stan Zinkowski has a couple videos using an argon flood in the oven to get rid of the oxidation. Check them out. Hope to see you at the Bar-Z S Bash. Jon
So the idea of the hard sheave ruining the rope is valid on paper but in reality if its a clean machined surface cradling the rope nicely, its not going to damage it. Furthermore if there is damage you will start seeing frayed strands on the rope and that should alert you that repair is needed, and given the safety factor, you should never really be at risk. Also that rope is pretty hard itself and is constantly being wrapped around its own, abrasive self, without issue. Thus I conclude that the issue of the hardened sheave, is actually a non-issue.
Hey Adam, greeting from west coast of Canada. I have been watching your videos for the last couple weeks now after having stumbled across them and I really enjoy watching. I haven't done any kind of metal working since grade 9 high school but I find them very informative and engaging and I do love how you explain everything you're doing. Keep up the great work. Thanks.
So I was interested in your Hardness testers and did a little Amazon/Ebay research. These things are breathtakingly expensive! That small simple looking PTC 316 Hardness tester costs $800! The files are more palatable at $142. And those bench top testers? Used ones START at $1900. Take good care of those things. Adam! At those prices I guess you really have to have a need!
This was a great video Adam! It was really cool to see the whole heat treating/ machining process on these parts. I can’t wait to be able to afford one of these ovens from Stan for the shop someday soon!
Just thinking without knowing, could the harder spots be from the tool you used to hold the sheave while dunking into the oil to cool? Really enjoy learning by watching your videos.
Adam you have to get yourself a steel tank for fab one for the quenchant. If you accidentally dropped that in there it would have been a real pain to clean up, not to mention getting hot oil over your boots. If you feel a bit lazy (I'm sure you won't and will design something much cooler) then get some 20mm ammo cans from the surplus shop. Steel and have a sealable lid to keep the oil from going off.
Couple things; First, its good practice to remove the scale from the heat treat procesz before testing for RC. Second, to remove the discoloring from tempering an old job shop trick vapor or sand blast. That works when welding to makes the work piece all the same "color." Mike - Plus8Precision
Just an Idea, while part is in oil, the pliers are covering very large part of surface, you should have a wire hook or something to minimize different cooling rates, cover minimal surface are.
Adam - a few things I would suggest: 1) Your oil reservoir is pretty small, so you have to consider that the amount the oil temperature around your steel is going to increase significantly in the first fraction of a second. I would consider a larger quench with more oil and preheat the oil and stir it ahead to ensure temperature equilibrium to avoid cold spots during quenching; 2) You are carrying your heated steel pretty far in tongs, which is going to act differently than the steel that is exposed to atmosphere directly, not to mention rapidly reduce steel temp and the safety concerns, I would consider changing the location of your oven/quench and use a tong or hook that minimizes surface contact; 3) You appear to be quenching in a plastic or pvc container on concrete - I would seriously suggest switching to a steel container and keep a chemical extinguisher nearby, as oil fires are often combustive and all it takes it for you to bump that container and it will likely melt a hole and then you have a hot oil spill; 4) I would also suggest wearing a filtered mask, not just a face shield, as burning/smoking oils are not so good to breathe, whether in the kitchen or shop.
i completely agree with this comment the heat treat could have been done a lot better and more efficient.. and the whole not enough oil thing is right but at the same time hes not taking .100 thou or anything too aggressive and its not a big piece of material but anymore then that yeah hed be chasing his tail till the part was scrap! dont get me started on the ambient temperature of a machine lmaooo!!!!!!
Great work there, as always.
There is a decarburized scale layer on the outside, yes. It will definitely throw off the reading, but its only a few thou thick.
The grey spotty texture is martensite. Good sign that the heat treat was successful.
For the quench - 40 to 45 is quite ok for a piece that size. Large pieces lose a lot of max HRC due to pretty much annealing while still in the quench due to residual heat in the center.
Still, you 're not quite there, yet - 4140 is supposed to harden to 50-60.
Your quench technique is fine, but you lost a lot of hardness in the transfer.
First - get your oil right next to the oven, or the oven next to the oil if you want to quench outside for smoke reason.
The goal is to pretty much open the door and drop it right out of the kiln into the oil in a blink of an eye.
If you need more than 2 seconds for a transfer, it's pretty much too late to get a good result, already.
Also - get yourself a metal bucket - if the plastic breaks (or you get contact and melt through it), you get a spill of hot, and maybe even burning oil.
That hard spot is from your tongs you need to preheat your tongs before you grab anything hot or you lose heat to the tongs great video
Yup I was going to say the same thing.
I am not a machinist myself, but I love watching you explain and do stuff. Thank you.
Same here. Grew up with my dad taking me into the metal fab shop 3 or 4 times a year, worked there two summers. Still remember the smell of the oil and grease, metal shard hitchhikers in the soles of my boots scraping the concrete or pavement. Great people to work with. Love seeing Abom's work in his vids from a raw forging to perfection.
Hey Adam, not to be overly picky but for more accuracy; when doing the hardness testing with that calibrated spring punch, you should make sure that the test piece is lying on a flat, hard surface. I believe that plastic tray absorbed some of the penetrating force of the punch. When you punched the second sheeve, i thought I saw the tray bow flatten a bit. This will affect the hardness test.
As a double check, you could take the calibration puck from your PTC kit and run it in your other Rockwell tester. Just an idea.
Adam, I'm suspicious that the area of differential hardening may be due to you grabbing the part with cold tongs. When I heat treat (knives and edge tools), I make sure that my tongs are quite hot, almost glowing red themselves.
Seconded, as well as a recommendation for a larger quench tank and more vigorous agitation. With anything that chunky ensuring really good even contact with the oil is huge.
Exactly my thought.
Also the oil was a bit far away from the heat treating oven.
@@thereddufus The tongs being cool wouldn’t be as much of a factor as the size of the quenching tank. The volume of oil and the lack of good convecting flow of the quenching fluid would be the biggest factors in inconsistent cooling rate leading to differing phase change progression and different final phase presence. Thus causing the varying hardness.
i worked in a heat threating company for 5 yrs doing the tests u should allways clean any millscale or any type of residue on ur parts before testing and allso im pretty sure that the "raised discoloured" area is where u had the thongs and it held in more heat than the rest of the part we used #9 steel wire to attach it or and lower it so the part would cool down all at the same time in the quenching liquid
Ultrasound durometer, like UCI 1500 is usefull for that ?
Your idea about scale messing up the readings is correct. I use regular sandpaper to clean the surface before measuring. Make sure that the surface is parallel to the measurement axis, clean surfaces and support workpiece properly. Still you might want to make multiple measurements as the hardness measurement is very sensitive to different variations. Maybe you could acquire a hardness calibration piece to check your measurement. With handheld hardness testers it is a must have as it is easy to start second guessing yourself while measuring.
This is why hardness requirement has always a tolerance. I have been using and have seen +2 -2.
Your tongs insulated that part of the steel. And created a Hamon, It cooled at a different rate than the rest of the steel. Use a wire Hanger or Pre heat the tongs and oil.
These two videos are like an advanced course in machining. Thanks very much for your continuing generosity in sharing your expertise and experience.
Pre heating the tongs and oil and keeping the oil close to the oven should give a more even hardness.
The uneven results are probably due to the uneven cooling and quench.
Had those issues with the first couple of heat treatment cycles I did.
I have no real knowledge of this sheave, however I know that a lot of cable type lift equipment is designed to have the sheave wear, and not the cable. be careful changing the design specs. love the videos Abomb. thanks and keep up the great work.
hmm good point
Yep, I am afraid 45-50 HRC is way too hard for this application. Standard 4140 bar stock is around 12-15 HRC. Probably a better choice. I think the cable would agree!
Adam, here is a thought. You mentioned that one area of the part had a hardness of 62. Could that be the area that was in contact with the tongs used to remove the part from the oven ? The heat transference from the part to the cold tongs may be the reason for the higher Rockwell rating in a small area of the part.
That's exactly what I wanted to write.
Couple of ideas re quenching your parts: First of 4140 is not the best of materials for this purpose due to low carbon content. It will harden, but do not expect tool steel hardness levels. Secondly, when you heat your parts for long time, decarburization happens in the top layers. Basically you loose carbon from steel thus making top layers softer (regardless of the scale). As others mentioned, keep your oil bath as close to the furnance as possible. I would personally try running some tests with smaller parts and if you want to use 4140 try quenching in water as well. Anyway it was a enjoyable video, good job Abom!
4140 is an oilhardening steel as per material specifications. water hardening can lead to cracks in the part. to avid decarbonisation either use an oven with inert gas atmosphere (expensive) or toolwrap (cheaper, but not feasible for all geometries).
This steel has .4% carbon which is easily enough for decent hardness while cromium and molybdenum make it less brittle.
Exactly what you would want for the purpose of the part decribed, so choice of material is good. Typical application for a tempered steel grade. Very similar to the 41CrMo4 /1.7223 we use over here in Europe for the same kind of applications.
There are detailed tables regarding how long it takes to heat through the whole part depending on wall thickness and which temperatures to use as wella s which quenching agent and so on. If you adhere to those you will get good results, otherwise you will not.
It was to hot also 1500 on that steel is enough
When you dip the larger parts to you move it in a circle. If you don't the you will get gas pockets around the part and it will cool slower. On 1040-1060 you can do a saltwater bath. You can always do a magnet test before the quench. This will make sure your at the right temperature to maximize hardness. Love your clips I learn so much from you.
Hey Adam,Directly after you harden the parts at 880°C for a minimum of 1 hour (the longer you leave it in, the deeper the hardened surface will go it is a case harden steel). You need to heat your oil to 360°C, quench and keep the parts at a constant temp for at least 2 hours then cooled to room temp for 4140 1.7225. This is the austemper temperature. You should be getting 61HRC after hardening. The steel is not hardened completely, you can still cut it with a conventional laith. Normally hardened steel to 58+3 HRC needs to be cut with a CBN or diamond insert using HSC. Normally you should grind the parts afterwards, and leave a good 0.6mm extra mass for clean-up.
You should also do a magnet powder test to check for cracks.
That high of oil temp is totally unnecessary, depending on your industry and country and code of regulations you follow. We heat treat 4140 all the time and it is quenched in 150F oil, and is supposed to be from 140-180 max.
@@Sffker normally you're supposed to use a heated salt bath (like we do at work).
You have 2 possibilities,
1) you austenize (minimum 60 min), quench, then temper in a heated bath 360°C-480°C minimum 2 hours
2)austenize (minimum 60 min), quench, and temper in an oven at 680°C for minimum 2 hours.
The data provided is the temperature, specifically for an oil quench and not a salt bath quench.
According to my machinist handbook they state 42CrMo4 material number 1.7225 (AISI 4140) harden at 880°C quench in water or oil, temper between 540°C-680°C (lower temp for water quench, higher temp for oil quench).
The 4140 hardens through tempering. Hence why Adam doesn't have 58+HRC.
Depending on application, the best results come from an oven using nitrogen, quenched in a salt bath, tempered in a salt bath. Up to 61HRC. The raw steel is delivered with a 53HRC.
@@chronicblazer84 Well he showed your last statement to be wrong. His was far less than 53 to start with. I have gotten 4140 steel in both a soft state and a hard state. 24" rod I have chucked in the lathe right now is toward the hard end of the scale. The other chunk I machined recently cut like butter with the same tool. Even just center drilling this new piece told me this one was different hardness to start with. Atlas Steel provides theirs as hardened and tempered. Different sizes also are delivered as different hardness-es. Others may supply theirs as annealed. Or as Atlas says, it can be annealed, machined,and re-heat treated to get to a harder level.
Does that hard, raised spot correlate to the tongs gripping the part by chance? Changing temps unevenly? Spitballing.
This scope Adam is mind blow... We have learn from you about tools that we couldn't ever imagine that exists. A big thank you!
Just recently "discovered" you. You're a natural teacher and craftsman. I'm retired but later in life did precision assembly and machining of smaller parts. I wish I had discovered you when I was doing that work - you would have improved my work!
Thank you for doing videos at this point in time, it's a welcome respite to watch while under COVID-19 house arrest. I especially like the actual machining parts when you make the chips fly!
Try fishing your job out and quenching, using a 1/4” hook. The wide tongs may cause varied quenching spots. Also in Australia we use K-type oil, i think your equal is Parks 50. You need a fast oil.
I love your work Adam, handmade with care, skill and pride.
I know I commented prior to this and I don't mean to beat this to death but I remember probably early seventies we needed to open up a sheave from 3/4" to 7/8" to accept a larger wire rope.. The sheave was out of a Lima crane and it was so hard in the groove that the groove had to be ground to size...Machine shop in Baton Rouge did the job...Cheers; Mike in Louisiana
I have been heat treating similar size parts for a few years now, all 4340. As a guy who has had parts slip out of the tongs, I cringe and hold my breath watching you quench in a plastic bucket. The steel safety cans with the foot operated lid work great.
I enjoy you're showing us your learning in the heat treating. I think the tool you used to hold the part did a much quicker temperature drop so it harder there. That spot you show in the beginning. I didn't see if it is symmetrical, on both faces. Stephan Gottewinter uses steel wire, hooks. I used them too in forge treatment and they work better for me. Thanks for the vid !
Hey ADAM! The differential hardness you noticed may be due to your tongs, and the 'long' walk to the quench. Quench needs to be right next to the furnace, and quick. Practice the moves like you would for a critical weld. Use a metal quench pail with a proper lid. You're on the right track with cross referencing your instrumentation. Can't wait to see you discover case hardening. Make tools from nearly any steel!
The tongs are insulating the part from the oil, a metal bucket w/ lid and a basket to lift the part out would be ideal.
@@j-man72b72 right. What little I did in shop and for a hook and shackle company I know the heat to plunge time and orientation is critical. Long parts must go straight in to the oil and maybe letting it drop off the tongs would work better. We also found after quench if the batch was crated and taken outside in a snow storm the hardness went up the Rockwell scale.making them more brittle and lower on the maximum pull strength range. Also Rockwell numbers are not possible to get on round parts of a sample. You need to grind a flat for Rockwell or Brinell
Always good when 1 test verifies and confirms another. Builds confidence in your equipment, too.
The tongs don't allow the part to cool evenly in the oil quench.
Run a piece of wire through the hole in the part before you put in the oven and grab the wire with the tongs to remove it from the oven and quench it.
Your quench tank should be metal not plastic. The part can melt a hole in a plastic tank.
That may be the only bit I remember from art school WAY back .... (Fire was the cool new tech). I had a nickel part explode because the tongs were such a great heat sink.
Thanks for doing the cross reference with the 3 hardness testers, it was great to see they all said the same thing.
I really like how you are checking and talking about the hardness. I wish you could go see the parts or have them brought back a few years later to see how they held up.
Thanks for taking us through the heat treat process and testing using various instruments, well done 👍 learning a lot from your videos (lessons).
Nice job. I am not a machinist but your work shows the knowledge and skills that you have.
I don't know if there is another channel where I enjoy learning this much about things I will never need to know. Thanks for the content!
Temper for 90mins bud
Your right about the scale affecting test results
Your hard spot may have been either the part that hit the oil first or it may have leeched carbon out of your tongs somethings caused an inconsistent quench but nice work all trades in house is the way to go
you might consider a metal bucket for your quench oil Adam. I remember Brian's plastic bucket melting when his oil caught fire.
great video as always
Be sure to keep cardboard boxes handy to use as fire extinguishers just in case. :-) lol
Not a machinist, but I really enjoy these videos. Thanks
I'm really looking forward to seeing Adam climb the learning curve and see his heat treating skills improve. It's great watching someone so knowledgeable in something picking up a new skill and seeing that process.
You did grab the sheave with cool tongs. That likely quenched faster than the oil bath in two spots. One on each side.
Adam, I love your videos, and I’m very impressed by your attention to details and strive for accuracy. I’m an industrialist at heart and my parents were engineers, so sharing your skills and day to day work activities allows me to live vicariously through you haha
Having said all that, I also wanted to suggest that you get a metal bucket or non-meltable container for the quenching oil. The plastic pile is a trouble waiting to happen. Keep up the great work, and the videos coming.
Thank you and stay safe.
Usually sheaves that run constantly are hardened in the groove for long life otherwise the wire rope will cut grooves in the sheave and the rope life running over such a groove will be lessened....This is for duty cycle work such as draglines, clamshell machines, magnets, etc where cycle time is two minutes or less .. Rope is constantly running back and forth on these sheaves....Mike in Louisiana
Finally someone who knows what they are talking about!!
Thanks for your comment, a refreshing change from the people saying the complete opposite and have no data to back it up.
And it's usually induction hardened and just on the surface of the groove down to about a quarter of an inch below it
Thanks Adam, very entertaining. Now I want a heat treat oven.
When I use a big assed wrench in order to send a bolt nearly to bolt heaven, I say that I am doing an ABOM to it!
Your DAH BOMB abom! That was a wicked quenching!
The hard spots are from the metal decarbing because it wasn't wrapped.
Eta: look up nucleation carbide.
The hard area is where your tongs were when you quenched the part. I recommend you drop the hot part into a heavy wire mesh basket and use an aerator in your quench bucket.
How deep does that hard area go? All the way through?
This would make it softer, no? Even on a thick part with all of that heat inside, the tongs will do that?
I only know a little bit from making knives, but typically people would feel that the tongs would act as a heat sink if anything, so the part would lose heat faster there and not harden properly. That’s why a lot of people will stick the tongs way into the quenchant just in case, so that the tang isn’t slowed in cooling.
It seems extreme to me that tongs could cause a difference of 20 HRC. Maybe I’m that ignorant though, that’s why I’m honestly asking. Maybe this steel is a very slow hardening steel?
That nice music just go perfect with a classy channel and guy as Adam. It's relaxing and soothing
Great job Adam , l like the clarity of your explanations. I only have a home hobby shop , but what you teach comes in handy . Stay safe brother .
Richard Palmer do you also watch AvE? Great tips there for home cookers
Great tip on the lower cost options for hardness testing! Great video!
NICE JOB! FINISHED THEM OFF NICELY THEY TURNED OUT AWESOME!!
the best thing about oil quenching with a plastic bucket is when you touch the side of the bucket and the part blows it out and you have a flaming oil avalanche on your hands. that is, your metaphorical hands. it's on your literal feet. i've been there.
also i have no clue why you're getting the results in heat treat that you've been getting, provided everything is calibrated. granted, i rarely bother oil quenching anymore and generally do air or water. but i do know that if you test it without removing the scale it reads high, usually off the scale high, unless it cracks under the force of the diamond, then it's just a random reading
edit: watching again, the only thing i do different is hang the parts from stainless safety wire, so it may have been that.
Heat treating is something I've always wanted to learn how to do. Can't wait to see you do some tool steel in it!
Very informative! But you might want to use a metal pail for your quench oil--if the part slipped out of your pliers it'd melt right through the bottom of a plastic pail, which would be messy even if the oil didn't ignite as the oil level dropped below it...
I would recommend making a metal can and the basket. I know that my machining school had that setup.
Nice work, when the radius was roughed in the tool was just so smooth cutting that. Great to watch.
Hi Adam, great video and explanation. You have skills. We do a lot of machining of various tool steels and we use a prehard NAK55 which is 40-42HRC. It machines excellent and does not need heat treat so you can go right to size after roughing. Its great for polishing, welding, & is very stable.
Enjoying the vids man! Keep them coming I need some quarantine entertainment
I’ve learned a lot from your videos in the past, and today I’m learning even more. Homeshop heat treatment of 4140 has always interested me, but I don’t have the equipment (yet). Thank you for taking us with you on this learning curve Adam !
I am curious to see the hardness where the tongs gripped the part during quenching.
That was what I was thinking too, I'm unsure if the tongs would have cooled it quicker or if they protected it from the quench. I was wondering if it might be better to use a bent rod and hook it through the middle hole.
I was thinking the same thing. I'm wondering if that's the harder spot, where the tongs gripped.
Adam, It would be cool to see your parts in action. As always great content.
Hey Adam
Started watching your videos about a month ago and I've already seen about 75‰ of them. About 20 years ago I worked at a place called GKN Driveline in Bowling Green, Ohio running CNC milling machines. I really enjoyed it and excelled at it quickly. I had forgotten how much I really loved it until I found your channel and now I'm thinking about getting into it like you. Anyway, love your videos and notice your picture with your Dad and Grandfather at the end of your videos. I would love to hear more about them and how they taught you what you know. Thanks brother. Keep making these awesome videos.
Now that’s a pipe wrench!! 💪🏼💪🏼. As always, I’m learning something new with your videos.
Hi Adam, you might be able to use some TIG Cups to hold your parts up higher when heat treating so that the whole part sits in the same heat layer in the oven.
Just so you know and how this passes on to all I ordered a bag of the lump charcoal from your Amazon store and it is of very high quality to cook with. Not to forget to mention the turn around time from order to delivery is superb. Very excellent to have a place to order that helps perhaps in a small way but does help support the channel!
Thank you. I order from those links all the time myself. 👍🏻
Great video. Loved the glimpse of the chip on your shoulder ;-)
Leeb (bouncy ball) hardness testers are also a good low cost options for flat surfaces like that. We use a portable digital ultrasonic hardness tester which is a bit more but less than a conventional hardness tester and more versatile.
Ultrasonic hardness tester are useful for measuring hardness in knives ? What do you mean about ? any model to recommend?
Abom: puts mat down under bucket of oil in case of mess.
The only oil that splashes out of bucket lands on the concrete beside the mat.
Ohhhhh Murphy, what would we do without you?
We would blame O'Toole.
@@gravelydon7072 My father says he doesn't run by Murphy's law. He says that O'Leary's law is more accurate.
Apparently O'Leary's law states "Murphy was an optimist".
Adam I'm still figuring out how to contact RUclipsrs real time and this is the closest I could find. I just wanted to tell you how much I envy how you got to learn and work with your Dad and Granddad. I've always liked family businesses, it just seems more American to me! Thanks for all your work and content brother!
At Waner & Swasey they used another type of hardness tester that used a hardened ball bearing. The bearing was dropped in side the gage when the gage rested on the work piece. It measured how high the bearing bounced inside the gage to a scale on the gage . They used it to test the hardness of their bed ways after induction hardening. There seems to be a lot of different types of hardness testers.
If I happen to be away from the shop and have a press fit bearing, I use a can of air duster, available for cheap at Walmart. Turn the can upside down and spray the outer bearing race until it freezes, usually about half a can, then it will drop right in with little or no trouble.
That’s a good idea actually.
@Abom79 Thanks for educating so many of us RUclipsrs. If it was any kind of automotive part, it would have a snap ring. Cut a groove in the other one. Axial-radial load test.
Great video Adam, I like that you're showing some new and interesting stuff. Well, it's all interesting! 😀
Enjoyed the project and came out beautiful.
You da man Adam!!!! love learning from you mate!!! Keep safe brother and keep going.....
Thanks for keeping us entertained, Adam.
I’d just toss it in my oven for 20 minutes at 400 degrees, with a bit of BBQ sauce and spicy Cajun seasonings! Don’t forget to cook up a good helping of niblet corn and Mac-and-cheese as sides! 😁
Hey Adam, love the content. Thanks so much for your hard work! Just one thing, not totally cleaning up the edge of the sheave was killing my OCD!!!
Hi Abom, here's a thought that has just occurred to me. Where you get that hard spot in the workpiece, could it be where you grab it with the tongs? After all they are much colder than the workpiece and would start to cool that point right away, before you reach the quenching oil. Then where the piece is still held by the tongs, could that cause some uneven cooling?
Adam: Two suggestions. Get a metal 5-gallon bucket for your quench. If you touch the side of the plastic bucket with the hot metal you could melt through. Second, move the quench bucket and the furnace closer together. What causes the scale is the oxygen in the atmosphere, even for that minimum few seconds it takes from furnace to quench. Stan Zinkowski has a couple videos using an argon flood in the oven to get rid of the oxidation. Check them out. Hope to see you at the Bar-Z S Bash. Jon
New intro music is pleasant.
As always, love watching the machining.
I would bet that area on either side is where your tongs were holding it and those spots cooled different than the rest of the piece
Yeah I was thinking the same.
So the idea of the hard sheave ruining the rope is valid on paper but in reality if its a clean machined surface cradling the rope nicely, its not going to damage it. Furthermore if there is damage you will start seeing frayed strands on the rope and that should alert you that repair is needed, and given the safety factor, you should never really be at risk. Also that rope is pretty hard itself and is constantly being wrapped around its own, abrasive self, without issue. Thus I conclude that the issue of the hardened sheave, is actually a non-issue.
Let the man play with his amazing toys
You are a brave man using a plastic pail to quench your hot part. Don't drop the part.
Great work Adam. Looks nice and it hard. Great machinist skills. Thank you for sharing.
Hey Adam, greeting from west coast of Canada. I have been watching your videos for the last couple weeks now after having stumbled across them and I really enjoy watching. I haven't done any kind of metal working since grade 9 high school but I find them very informative and engaging and I do love how you explain everything you're doing. Keep up the great work. Thanks.
You get a great finish on the 4140. Good results for hardening 4140.
Yep, 4140 can be tricky.
So I was interested in your Hardness testers and did a little Amazon/Ebay research. These things are breathtakingly expensive! That small simple looking PTC 316 Hardness tester costs $800! The files are more palatable at $142. And those bench top testers? Used ones START at $1900. Take good care of those things. Adam! At those prices I guess you really have to have a need!
I can see you've progressed with your quenching technique following an 8 pattern
Looks great. If you will, let us know the outcome once the customer puts them to work for awhile.
As always, great video man! I hope you're saying safe and healthy during these crazy times.
This was a great video Adam! It was really cool to see the whole heat treating/ machining process on these parts. I can’t wait to be able to afford one of these ovens from Stan for the shop someday soon!
Best machining channel on RUclips....although Keith Rucker is a close 2nd. :)
Don’t let Keith see that 😂
Hard to pick between Abom79 & This old Tony I love both channels
Adam, Really enjoyed watching your video/project, thanks for sharing your video.!.!.!.
Just thinking without knowing, could the harder spots be from the tool you used to hold the sheave while dunking into the oil to cool? Really enjoy learning by watching your videos.
>> 5:20 yes, that could be it, but on the surface on the work that doent mater, just looks
In other projects it could make all the difference.
Adam you have to get yourself a steel tank for fab one for the quenchant. If you accidentally dropped that in there it would have been a real pain to clean up, not to mention getting hot oil over your boots. If you feel a bit lazy (I'm sure you won't and will design something much cooler) then get some 20mm ammo cans from the surplus shop. Steel and have a sealable lid to keep the oil from going off.
It's fun to watch Adam out there workin while I'm stuck without a dang job. It feels like I'm doing something when I watch lol
Well learning is still doing something I guess!
My dad always said to me, "if you have a day when you don't learn anything, then you've wasted a day"
Has shop with tens of thousands of dollars in equipment. Uses phrases like "septic tank lowering machine" lolz I love this guy.
Couple things; First, its good practice to remove the scale from the heat treat procesz before testing for RC. Second, to remove the discoloring from tempering an old job shop trick vapor or sand blast. That works when welding to makes the work piece all the same "color."
Mike - Plus8Precision
Just an Idea, while part is in oil, the pliers are covering very large part of surface, you should have a wire hook or something to minimize different cooling rates, cover minimal surface are.
the "raised"raea might be where you where holding the piece with the tongs
I wonder if the different hardness reading in that one area is something to do with the tool that was holding it when it was quenched?
Or the orientation while sitting in the heater.