Home Forums Hunting & Shooting Gunsmithing Firing pin steel

Does anyone know what kind of steel is/was used, by manufacturers in the making of the long firing pins found in bolt action rifles such as Winchester, Remington, Savage, etc? Also if you know, do do know what the heat treatment process is?
Your assistance is appreciated.

I cannot tell you the exact type of steel used, but at a guess, it would be some type of steel that resists breakage and deformation due to impact. Maybe some type of chisel steel.

The heat treat would fit the same parameters; heat treated to a hardness that would resist breakage and deformation.

I have often wondered about this myself. I have seen some very old guns which I know have been both live fired and dry fired many times, but the striker and firing pins are still intact.

I would think the same type steels and heat treating would be used in revolver and shotgun hammers and the strikers in shotguns.

It would seem that the firearms manufacturers took a lot of pains to develope a steel that would withstand shock over many years and many cycles.

This is pretty good stuff for firing pins. Making the part is half the battle, proper heat treating is required to make it tough enough to withstand abuse.

http://www.brownells.com/.aspx/pid=588/Product/OIL_HARDENING_DRILL_ROD_ROUND

So far my research is pointing toward chrome vanadium steels like SAE 6150.

All I can say is having made a gazillion, with a "G", small pins and impact resistant parts over the years, O1 and W1 work great!

I am sure it does thanks, however that wasn't the question. I am interested in what the manufactuers use.

I am not making replacement parts.

Then maybe you should ask the manufacturers if the experience of our resident gunsmiths isn't good enough for you.

I think you are on the right track with 6150. It would need to be a low carbon steel, for the impact resistance. I doubt if the manufacturers would tell you, but if you had a way to do it, you could have a firing pin analyzed for element content.

O1, W1, even common nails have been used, and I have made a few firing pins from those hard nails that can be driven into concrete. Any of the above will work for a while, but I don't think any of it would be as good as what the manufacturers use.

I read an article many years ago, where a firearms designer tested several steels for use such as you describe. O1 was one tested, but repeated strikes caused it to chrystalize and finally break. I am not sure, but I am thinking they finally went to one of the S type tool steels, or possibly an SAE type, as you mention.

Interesting question.

Well, look at all the old Mausers in the world. They had plain carbon steels, used medium carbon for about everything on a rifle. O-1 would certainly do the trick, it's not a very demanding job particularly when compared to, say, a punch press die. Spring temper if you like though I doubt it's necessary.

Oh, don't know what manufacturers use but I wouldn't be surprised if it was plain old 4140.

1234567,
Thanks. My question was in search that maybe someone here had knowledge of the answer for this question. Do you remember what the article was that you read?
The 6150 comes from a book on LC Smith shotguns and contains the blueprints for the various part. I believe there is a book about the manufacturing of the Springfield rifles and I was hoping someone has it and has knowledge about whether it says something on the subject.

Nighthawk,
And thank you also. SAE6150 is a spring wire type steel and I believe they use it to get some of the those qualities. O1 can also be used but must be drawn at a high temp to get some spring properties. I built a German style 16th century wheellock a number of years ago. Since the mainspring was massive and I couldn't get 1095 of adaquate size I used O1 for the spring. I don't remember the draw temp but I believe it was close to a 1000 degs F. But my memory may not be exact here.

LRF:

The article was in a Gun Digest from at least 30 years ago. I can just barely remember it. I do remember the author stating that O1 appeared to be a good steel for certain applications, but the constant shock from firing and the hammer falling eventually caused it to fail. O1 is approx 1% carbon, which I think is a bit high for a steel that requires shock resistance.

I have Hatcher's Notebook, which has a lot of information on the 03. I will try to look it up tomorrow. I know there in information on the actions and barrel.

Crucible Steel makes the 416 steel used in stainless barrels. They might also make the steel for other parts as well. I do know that they, and others, make the steel used in CM barrels, 4150 or SAE 4350, or something like that.

You might try contacting Crucible. I think they have a very knowledgable technical department, but some of the information might be proprietory (Sp?) and they won't give it to you.

I assume you are going to start manufacturing firing pins. If so, I can see where you would need the correct steel, to prevent people from bringing back broken firing pins regularly. Firing pins seem to be very durable on the guns you mentioned, so they much be made from some pretty good (suitable) stuff.

Sounds like a fun project! Those big honkin' springs must have seemed like magic back in the 16th century.

My modest library turned up little, must be considered an arcane subject. On making replacement long pins, Dunlap in his old book wrote that he made them from drill rod and medium-high carbon tool steel and used a spring temper.

Perusing Brownell's catalog, Gre-Tan has a Rem 700 firing pin assembly with the firing pin made from 4140. Superior Shooting Systems advertises their speedlock assemblies as aluminum with 4140 tips. Wish I could be of more help.

A boy at camp, broke the firing pin on his model 94 Winchester rifle.
We took the rifle down to a retired gunsmith I knew and he machined a hole into the firing pin with a common drill bit in a lathe.
Silver soldered the drill bit into the hole.
Ground it to fit.
Pulled several bullets out of several cartridges and ground it down until it was the proper length.
In my opinion that firing pin was superior to any store bought piece.
The grandfather of the boy with the broke rifle, took the rifle to a gun-shop as soon as they got home from camp and had a factory pin installed.

The gunsmith that did the original repair has long since perished.
Heck - he was 85 years old when he fixed that rifle for the boy and that was 25 years ago.
I believe that it took him about 3 hours to do everything.

What this tells me is that the original firing pin was made of a very soft carbon steel that was easily machined.
What it does not tell me is what materials other gun manufacturers used for the same process.

Drill rod is easily machined and heat treated, but once it is heat treated, you are not going to machine it with a regular old high speed steel drill bit like a hot knife through butter.

Some firing pins I have saw were made from a 4130 chrome moly steel - but that was in a Remington or Winchester bolt action rifle and not in a model 94 lever action rifle.
So there is no right answer here.

The question is - what does it matter - if you are not trying to produce one.
It would be like me asking you - what kind of rubber is in my car tire?
Without giving the brand or model of tire - who knows.
Even if we knew the brand and model - most times that information is a secret because tire manufacturers are competitive by nature and they just don't give out their trade secrets.

What??????????? Daniel Beer, you are entertaining. In a sick way. Like laughing at people who are...who can't help themselves.

Who is this Daniel Beer guy you are talking about.
I just told you how the guy repaired a firing pin for a Model 94 Winchester 30-30 rifle.
Ripley's believe it or not - it worked like a charm.
I don't think you could wear out a drill bit shank - used as a firing pin and the quality of the materials - High Speed Steel is probably as hard as the bolt face for most rifles.

I found a picture of a short firing pin for a hand made single shot rifle. It was made from O1.

The specs. stated the tip about 1/4" long and was about Rc65, and the shank was about Rc45. This sounds about like the temper of the 94 mentioned above--hard tip and soft shank.

The shanks of HS drills is not as hard as the drill itself. They are made softer so the chuck will grip them. Try it yourself with a file.

A high speed drill shank, unless it is hardened, would wear quite easily. (I feel I am wasting my time explaining this as it will probably do a flyby)

The first complete firing pin I ever made from scratch was from 6150. It was for a '92 Winchester. That was while I was still doing my tool and die apprenticeship in the early '70's. It's still working today. 6150 would be my guess for the commercial standard.

LRF:

I did some searching on the net and I found three steels that offer good impact resistacnce. I copied and pasted this info from the Crucible site:

(AISI S5)

LaBelle Silicon #2 is a shock resisting tool steel capable of maximum toughness at relatively high hardness. It has excellent resistance to impact and battering, with good edge retention.

Typical Chemistry
Carbon 0.60%
Manganese 0.85%
Silicon 1.90%
Chromium 0.25%
Molybdenum 0.30%
Vanadium 0.20%
Typical Applications
Heading Tools Punches
Chisels Shear Blades
Rivet Sets Concrete Breakers
Stamps Hammers
Hand Tools

Here is another:

CRUCIBLE S7
(AISI S7)

Crucible S7 is a shock-resistant air hardening tool steel, designed for high impact resistance at relatively high hardness. It offers toughness to withstand chipping and breaking, combined with high attainable hardness and good wear resistance.

Typical Chemistry
Carbon 0.55%
Manganese 0.70%
Silicon 0.35%
Chromium 3.25%
Molybdenum 1.40%
Vanadium 0.25%
Typical Applications
Punches and Dies Subject to Heavy Impact
Wire EDMed Punches & Dies*
Warm Forging/Heading Dies
Plastic Injection Molds
Shear Blades

*S7 XL recommended for EDMing fine or intricate parts.

And another:

AISI O1)

Ketos is an oil-hardening tool steel which may be hardened from fairly low temperatures with little size change. This grade combines deep-hardening qualities with a fine-grained structure, affording good initial production runs, and good continued production after grinding.

Typical Chemistry
Carbon 0.90%
Manganese 1.25%
Silicon 0.30%
Chromium 0.50%
Tungsten 0.50%
Typical Applications
Blanking Dies Jewelers Hobs
Engraving Tools Paper Knives
Forming Tools Taps (Hand)
Gauges Trim Dies

Going by these data sheets, it would appear that either the S5 or S7 would be ideal for a firing pen.

The last thing a gun manufacturer would want is a truck load of their guns arriving every day with a broken firing pin.

I would not be surprised if many firearms manufacturers use one or both of these steels.

Google Crucible, and some of the other steel manufacturers for more information.

Hope this helps.