Firing pin steel selection

[Metaloxide]

Wednesday I'll be receiving five 1' pieces of 1/4" diameter 1144 steel, two 1' pieces of 3/8" diameter hardened multipurpose 4140 steel and one 1' piece of 1/2" diameter high strength 4140 steel.

 

[benmychree]

I think that whatever is used it should be heat treated; 4140 HT is not all that hard, perhaps about 32 Rc, I'd be thinking of making the part out of 0-1 drill rod, it is a true tool steel, I think I'd harden and draw it to about 35 -40 Rc.

 

[Metaloxide]

I think that whatever is used it should be heat treated; 4140 HT is not all that hard, perhaps about 32 Rc, I'd be thinking of making the part out of 0-1 drill rod, it is a true tool steel, I think I'd harden and draw it to about 35 -40 Rc.

The advanced gunsmithing book posted in this section agrees with you that it should be hardened.
I can't wait to get the order of steel to do some more work on it.

 

[Smithdoor]

I am working on restoring a particularly trashed FIE E15 revolver and one of the parts that I can't buy is the firing pin. I don't have a lathe but I made a functional replacement using a drill press and file out of 12L14 steel as a test. Now I feel confident I can make the part so I want to get a better steel for the purpose.
I ordered some 1144 rod from McMasters and I was wondering if it would be a good choice or is there something better available.
I am extremely limited in heat treating ability as all I have is propane and oxyacetylene torches and my wife's oven.
View attachment 484944View attachment 484945

I like O1 tool steel easy to machine and you can hardened the steel.


Dave

 

[mmcmdl]

Most of our Gubmint guns were 15-5 or 17-4 stainless roughly in the 45C range . The more exotics were Almar .

 

[pontiac428]

IIRC 17-4 is the spec for the M16.

 

[Ulma Doctor]

IIRC 17-4 is the spec for the M16.

Didn’t Armalite win the M16 contract for being the cheapest????
(Just poking fun)

 

[Asm109]

Best thing about 17-4 ph is the insanely simple heat treating schedule.

https://specialtysteelsupply.com/wp-content/docs/17-4ph.pdf

Buy your material in condition A
Then heat at temp in chart. Let air cool.
The number in each condition in the chart is the temp you hold it at.
For H900 the time is 1 hour. All other conditions the hold time is 4 hours.
With these low temps you don't have to worry about scaling of your part.
You can also buy the material pre hardened and machine with carbide.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[Metaloxide]

Best thing about 17-4 ph is the insanely simple heat treating schedule.

https://specialtysteelsupply.com/wp-content/docs/17-4ph.pdf

Buy your material in condition A
Then heat at temp in chart. Let air cool.
The number in each condition in the chart is the temp you hold it at.
For H900 the time is 1 hour. All other conditions the hold time is 4 hours.
With these low temps you don't have to worry about scaling of your part.
You can also buy the material pre hardened and machine with carbide.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

So I just want to make sure I'm understanding this correctly. For the h900 condition you hold it at 900 degrees for 1 hour?
I don't honestly think I could achieve that with the equipment I have currently. I've been thinking about building a heat treatment oven though I don't think I'll be doing that too soon.

 

[Asm109]

Yes. Hold at 900 F for one hour, ASSUMING you start with material in Condition A.
Or buy the prehardened stuff and machine away.