Dumb question time

[uncle jimbo]

Ok it is dumb question time.
I Have a small piece of metal that I want to make harder. If I remember correct, do I get it cherry red hot and drop into oil or do I drop it into water.
I use to know this stuff, but God I hate getting old.

 

[fiver]

they will both make it harder.
one moreso on the surface and the other gives better aligned internal molecules.

 

[Brad]

Depends on the material. If it is low enough in carbon it may not harden at all. If some metals it may need Water or oil to harden properly. Water cools the metal faster than oil.
Dont forget to temper after hardening as it may be hard but brittle.

Ketih can give you more info on this that’s you could ever want to know.

 

[uncle jimbo]

It is a firing pin out of a cheap 22. It peened over back when I use to shoot it. So I use a file and reconfigured it to the original shape. It would file, but took some effort to reshape it. And I wanted to re harden it before I tried to use it again.

 

[Bret4207]

You want it tough, but not hard. So you have to get it red hot and then quench. Oil or water really doesn't matter because then you have to anneal it. That means, after you polish it so you can see the colors change, slowly and carefully re-heat it until it starts to show a brownish yellow color. BUT! Remember the nose of the pin, the thinnest part, will anneal faster than the thicker parts, so as soon as you see it brown- quench in light oil. If you pass brownish yellow and it goes blue, start all over again.

 

[JWFilips]

You just need to oil quench for that Then polish it bright and heat it ever so slow until you see dark blue form.... then quench in water!
Heat before the tip so the very dark blue chases out to the end

 

[Bret4207]

I think blue is going to be too soft Jim. Firing pin out a cheap 22? Likely very soft and might not harden at all. Case hardening might be an answer. I know you've done a lot of gunsmithing. You might have a better handle on it than I.

 

[JWFilips]

Yes you can Case harden it with case hardening compound ....Now that you mention it That would be my choice for a 22 rimfire and a lot simpler!
Kasenit would do the trick in one step Heat metal tip of the FP dip in compound heat again and a crust will form the keep it at red for a few minutes then drop it in cold water you will hear a nice loud crack! Case hardened an ready for 100 thousand rounds easily

 

[JWFilips]

Brett on the first note Dark blue on a pin is not too soft It is only hitting a brass rim or primer However you are correct The metal in a cheap 22 rimfire pin probably would do better with case hardening!

 

[Bret4207]

Problem is he probably doesn't have any on hand. I had a can years back, no clue what ever happened to it or I'd send him some. I have no clue what a can costs these days.

On the pin, I was thinking that it's not hitting the shell that's the problem. It's the hammer, of what ever sort, hitting the rear of the pin and mushrooming it a bit over time and the steel behind the rim and it's eventual effect on the FP tip. If it's like most old RF's, someone dry fired it and that's why he's fixing it in the first place. I've found on a dead soft FP tip even with the rim as a cushion they distort over time. Maybe it takes more of some designs than others.

 

[JWFilips]

Brett Great observation!

 

[uncle jimbo]

Well it didn't take long for this thread to get over my head.

 

[RBHarter]

It's not nearly what Kasenit is , but , I did in a pinch use sugar once . I think a little powered sugar might do for the quest at hand . Just adding carbon to make a hard shell .

 

[fiver]

you can use kingsford charcoal too.
you still have to heat the part up to like 15-1600-F for the hardening to penetrate very deep.

 

[Ian]

I read somewhere that Kasinite is history but there's a substitute for it called "cherry red" or some such. Didn't check the webz to see though.

 

[Brad]

Cherry Red Surface Hardening Compound 1 lb

Cherry Red Surface Hardening Compound is an easy way to harden soft, low carbon metals. Cherry Red in combination with high heat creates a tough,...

www.midwayusa.com

Here ya go Ian

 

[Ian]

you can use kingsford charcoal too.
you still have to heat the part up to like 15-1600-F for the hardening to penetrate very deep.

Yep. I made a "pipe bomb" with a special form cutter in it that I made out of mild steel. Packed with crushed Briquets and threw it in the pottery kiln for half a day and let it air cool, then reheated with a torch and did a water quench. Didn't bother to anneal because it was only cased. Touched up the edge with an Arkansas stone and it was hard as a coffin nail plenty deep enough for the job.

 

[Bret4207]

$34.00 for a can of that stuff, Kasenit is probably more! Uncle Jimbo let me look and see if I can find that can of Kasenit I had, or maybe someone else has some. All you need is a tablespoon or so worth and that will still leave you with 7/8ths of it left over.

 

[JWFilips]

Ok I just read the above post and thought I could help out! Went into my shop to cabinet that holds my Kasenit Jar and there was an empty hole! Now I remember loaning it to someone but I have no Idea who so Now I'm going to have to replace that and I'm shocked at the prices. I bought my original bottle back in 1983 and the price wasn't painful!

Seriously I always thought it was made out of powdered bone charcoal ground up vegetable tanned leather and sugar judging by its smell when heated!
I can't even tell you how many Frizzens I case hardened over the years using fine granular charcoal (from Small water filters) and chopped up leather packed tight in a Campbell's soup can and folded closed and placed in a small bon fire for about 1 hour and then pulled out.... puncture the can and drop in a 5 gal bucket of water

 

[Bret4207]

I can't find my can either Jim. That means I probably haven't unpacked it from when I moved here 25 years ago!

Uncle Jimbo, if no one else can help you you can try Jims recipe and it might well work. All you're doing is transferring a bit of carbon from the mixture onto the outside layer of the pin. It's really not rocket science and case hardening would be a very good method of giving you a tough but impact resistant result to your FP.