Hardening a Firing Pin???

[Virgil Ray Hality]

I have one from VTI,  It is a replacement for my Open Top and the pin is in the white.  Now that I have it shaped to my liking, I need to harden it. 

How does one do this?   

[Bull Schmitt]

You might want to check with VTI. The hardening process varies depending on the type of steel. Most involve heating the part until it is red hot first.  Steels that are "air hardening" are left to cool and that is it. Other steels may require quenching in either water or oil. Again depending on the type of steel it may be almost brittle after quenching and will require annealing. Annealing requires heating to a certain temperature and then allowing it to cool slowly. To simply care harden there is a product called Kasenite that fairly simple to use.

Some spring steel responds well to heating to a bright read and quenching in either oil or water. Clean the piece to remove the oil or water and then immerse in molten lead for a few minutes to anneal it. IMMV

[Virgil Ray Hality]

Thanks for the tip.

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[Paladin UK]

Ho Bull.........

Ya say......

Clean the piece to remove the oil or water and then immerse in molten lead for a few minutes to anneal it.

Never heard of that before

Can ya tell me how doing this effects the steel

Paladin (Whats kinda nosey ) UK

[Bull Schmitt]

Howdy Paladin,

As an example, when you are working with spring steel (high carbon) the quench in water and/or oil can leave the steel very hard to the point of being brittle. Molten lead is at a good temperature  to partially anneal/temper the steel without overheating to the point of being soft again. YMMV

[Hemlock Mike]

Paladin --

What BS is telling you is true.  There is a whole science behind your questions.  I have made springs and you have to know what you have.  A 0.005% amount of carbon can make a difference to those atoms.

So far you been told true but with limited info for consideration.  I usually heat to red-orange heat and quench in water.  Don't squeeze it now - It will break like glass.  Polish it off to shiny and then heat for color change - MAGIC --I've done it and been happy.  A trip in melted lead pot might work....I'm gonna try it !!

Mike

[Judge Lead]

I have turned up a couple of firing pins for my Hammer S/Gun. When I had it right, I tried it in the gun and the ends burred over as they were far too soft. Cleaned them up (I did make them a little long as a trial) and heated to Cherry Red. Quenched in water, polished to clean shiny metal again and SLOWLY heated till they started to turn a dull blue. Removed heat and let air cool. Have had them like this for 18 months and had no problems.
When I did the second part of the treatment, I used a peice of angle iron, held in the vise with the pin in the valley of the iron. All I was doing was heating the angle. Never applied the directly to the pin allowing for a slow transfer. Used a propane torch as my heat source.

Regards

[Hemlock Mike]

These colors stated here relate to actual temperature.  Red, red orange, dull blue all relate to old blacksmith charts for color temperature.  It may look like magic and in a way it is as learned from experiance but it does work. 
Modern metals and technoligy has more specific methods more exact.  Hardening metal is typically easy -- its the trick of drawing it back where the magic exists.  I like the judge's method for a dull bule color.  Let it cool slowly from there.

Mike

[Paladin UK]

Like they say ...

Yer never too old ta learn

And you pards have given me a brill lesson in Metalogy,

Pards...........  My hats off to ya`ll

Paladin (Whos glad he`s a cowboy) UK

[Montana Slim]

I'm somewhat suprised the VTI part wasn't furnished in the hardened state.
You really need to know the type of steel to harden it proper. If it is a low-carbon steel, the only alternative is to harden the surface, using a product such as Kasenit, or to use a carburizing flame (to add carbon to the surface) then quench.
Alloy steels (the good stuff) would require heating / holding at critical temperature (around 1400 F) before quenching in oil or water, again depending on the type of steel.

It might help if you share info about how you shaped the part, using a file, stone, emory-cloth?
Did it cut easily?

I haven't fooled with my OT's FP, but my R-M's pin's are definitely through-hardened, and made from a good grade of steel.

If push comes to shove, I'd recommend you use the Kasenit hardening. Beteen the carbon-enrichment/hardening at the surface (good for low-carbon steel), the heating/quenching involved (per the product directions) would improve the grain structure & hardness if it were a alloy-type steel. In either case (pun), you should have a more serviceable part. If not, you'll need a new firing pin in another 5K rounds...and you'll be even more expert at that time 

FYI, Reasonably good quality FPs seem to last 10-15K

Slim

[Virgil Ray Hality]

Well, VTI sold me one in the white and told me it was not hardened.  I shaped it wth a concave dremmel stone by hand.  I did not use the dremmel tool. It was not hard to "stone" this part.  I have an email into VTI asking what it is made of.  I do not yet have an answer.   

[Steel Horse Bailey]

Howdy!

If you can get a copy of "Machinery's Handbook"  (and hold on to your wallet pard, they're OVER $100 a copy!) there is a chart there that has the general colors and the associated temps when some metals are heated.  I have one of those books, the 16th edition, I believe, that my Dad bought in the early 1950s and it's amazing the amount of information is still current!  My copy has about 1200 pages, the newest ones (they're up to about the 25th edition) have over 1700 pages!

It is considered the machinest's Bible.

As others have stated, you need to know what you're working with, then you can heat it and quench it to harden it successfully.

[Virgil Ray Hality]

Well, I have the hardened pin in the gun now.  After 150 rounds it is holding up and does not look the least bit "used".  So, I will see how my hardening actually holds up during the CAS season this year.   Thanks for the pointers everybody.

[Virginia Gentleman]

I have had good luck with the Kasenit and have restored some of the case color look with a wiping of old used motor oil and a quick pass of the map gas flame a few times with very satisfactory results in looks and strength.