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Curious on temper of a pin/ drift punch from coil spring 5160 I'm guessing

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This 2nd tool I have made in my new hobby and was wondering about the temper after the heat treat? I heated to a dull orange and quenched in preheated used motor but only up to the start of the taper.

 I heated the whole tool up and then let the radiant heat soak it's way up to the top.leaving the octagon section to just air cool to stay soft for the hammer blows  Probably a 5 minute process to let the tip turn to an almost dark brown/ purple color. My theory is it's going to be abused shockooaded/side loaded and would rather a softer rather than hard and have the chance of shearing. The parent spring is a 7/8 thick coil spring off an industrial vibratory shaker.

Before I worked it. I heated it to an orange just past bright red color,, straightened it and put it in my forge with the openings closed off to cool down slowly overnight. I don't know why but it seemed like a good idea at the time. 

Like I said, I was wondering about the temper to bring it too being a cold working tool that will be hammered, beat up and put away dirty. Thanks for the input. Here's a couple pics if your curious. 




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Also: you have definite knowledge that the spring was 5160 or are you assuming it was as many springs are?

Also, any decarburization during forging that was not removed in the finishing?

When working without solid information; junkyard rules apply---and that means TEST IT and modify your process to deal with how it works in use. (Note that once you have dialed in the proper methods for your use on that piece then you have quite a bit more of the same stuff to use!)

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Many will say not to heat treat a hot punch or drift because you will lose your temper when you use it. I dont agree with this for 2 reasons. First, it gives you heat treating experience. Second, you may lose temper at the tip, but the rest of the tool is unaffected.

Heat treat here means anneal, normalize, harden, temper. I dont always normalize.

For coil spring i heat it to a bit hotter than when it loses its magetism. I quench in oil.

For punches and drifts i do a differential or"reserve heat" temper method.

I'll stick to a hand held hot punch about 14" long. I heat treat most of the taper, but only the bottom gets hardened and tempered. The rest is normalized. I quench about an inch and a half or so of the tip. Dont hold it still. Move it rapidly up and down, not sideways. Quickly polish about an inch with sandpaper or even a hot rasp. Watch the temper colors run.

When a straw color covers the end by  about a 1/4" or so, put an inch in a can of water and let it cool. Now you have a"normalized" taper and a hardened and differential tempered working end, and some good practice 

I also usually heat treat the hammered end. I dome it first with a hot rasp, then heat treat as above. Draw your temper to a blue or purple,, or even just normalize it. This will slow down the mushrooming that will happen when you hammer on it.

Hope this helps and have fun.

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This is very useful information. I can't for sure say if the spring is 5160. But it is very good steel that slightly air hardens, I determined this with a triangular file, I heard these are the hardest files. and I tested  a quench in water and it didn't like it at all, micro cracks so I determined it is oil hardening.  I was wearing my safety glasses too. I only got two eyes. Also the Sparks are very explosive like little sparklers going off, 

Also when planishing the hammer dents out is it ok to lightly tap minor defects out at a dull red to black heat? And since I'm not doing heavy hitting and forging can I consider this normalizing? Or is normalizing cycling from critical temp, or slightly past magnetic down to room temperature? Like I said. I will follow the junkyard rules of mystery steel. It is very high grade, new these babies cost $1600 Canadian so they are pretty high grade I'm guessing.

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Please remember that higher price does not equal usability for other items. It may be the absolutely BEST alloy for an industrial vibratory shaker but not be a good one for a drift.(I'd bet it would be; but I've lost some of those bets over the last 38 years... I generally start with a warm oil quench when "guessing", you can go more aggressive if that doesn't work; but it's hard to go gentler when the piece is now pieces...)

Many people seem to think that higher price must mean higher carbon; however  I'm sure you can get aerospace grade 1005 steels at a very high price; but they would not make a decent blade!

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On 8/3/2019 at 5:14 PM, BIGGUNDOCTOR said:

Triangular files are not harder then other files. Machinist files can be harder then woodworking files. It all depends on the manufacturer.

I heard because of the thin sections, the 3 edges, they get cooled in the quench a little quicker creating a slightly harder section after the heat treat. Learned this from an old machinist  but maybe he just made that theory up on that. Probably a case of bad information


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1 hour ago, Steve Sells said:

I get teased for my typos and then when I use a spell checker I still get it wrong

That's why I stopped caring too much.

Bustapepper: You REALLY need to stop guessing based on what guys who don't know what they're talking about know. How do you know water quenching that spring steel caused micro fractures? :blink: Struck tools isn't the place to guess. 

Small files are heat treated in a commercial facility to spec, how thick or thin they are makes no difference. Nicholson File company isn't heat treating their products in a mountain dwarf cavern.

Do you know what the mystery metal rules are? Do you know how to to do any of the basic tests? 

We love to help folks so please don't take it wrong when we tell you you're making mistakes.

Frosty The Lucky.

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I'm really new to all of this and appreciate all the input. I value all of it.  In reality I do not know much. I am learning as I go. I'd rather find out I'm making mistakes now and correct as I go rather than just learn the wrong way and then have an unstable footing too build off of. You guys are right. I don't really know the junkyard rules like I should, and I'm just going off of the steel has to be 5160 because that's spring steel. I did do the tests, but I don't have a known source to base my tests off of, my spark test cant be valued because I don't have a known source, I have read and have discovered that there are too many factors on used springs due to micro fractures and stress that will show up especially on a strucken tools at a later date and possibly be a hazard. I will keep educating practicing and asking lots of questions when the time comes. 

Like I said I won't take it wrong. I know it's all in good spirits to pass on knowledge to us rookies to have a good roots to build from. Thanks for that and always will appreciate the input


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We're all learning as we go. Some of us have just been going a lot longer than others. 

If you have unknown steel you have to test it by quenching it in different quenchants until you find which one works best. Same with tempering. There's a lot of info on here about testing mystery metals from spark testing to estimate carbon content to finding the right heat treating process. In the post titled mystery metal Jlpservices has a good description of the notch and break test. I would think you can do something similar when it comes to tempering steel also. After you know the right way to harden it you can temper test coupons and then break them to see what temper color works best for it's intended purpose. Good luck and keep learning, I know I sure am going to soak up as much info as possible.


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For what its worth its my experience that if it looks like a coil spring the heat treat process in my post will work. Its at least a quick and dirty place to start if you are new to the craft. Always have the confidence to take anything you learn from someone else and experiment if needed.

As for micro fractures. Always realize that these may exist. However ive learnrd that the more experience i got the less of a problem this became.  ;) So if you are a new guy, dont be so quick to blame micro fractures when your piece breaks, look more into your technique and work with this cheap and very usable source to gain experience forging and heat treating alloy steels

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