Case hardened hammer and trigger question

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greenhorng

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Why do you see case hardening on some stainless revolvers within the same model and others seem to have a stainless finish? For example, I've seen S&W Model 66's both ways.
 
S&W started using stainless to build guns before suitable stainless was avaiable to make hammers and triggers out of it.
Early guns maintained case hardened high wear parts.

Later on, they started plating them.

Still later they started using MIM hammers & triggers that are not case hardened but hard clear through.

rc
 
A bit of history might be interesting. In the 1920's American companies imported Spanish-made revolvers that were at best so-so and at worst cast iron junk. Many of those copied the S&W M&P revolver, at least in outward appearance, and were often sold as genuine S&W revolvers, at a quarter the cost of a genuine S&W.

One of the steps S&W took to stop that was to trademark its use of color case hardening on the hammer and trigger. If the Spanish continued to case color those parts, the guns would be stopped by customs for trademark infringement; if they stopped, the guns would not look like S&W's.

Unlike a copyright or a patent, a trademark is protected indefinitely, but in order to keep it in effect, it must be used and defended. Since S&W does not want to lose that trademark protection, they will keep coloring hammers and triggers, even though it is not really case hardening and the MIM parts are hard all the way through.

Jim
 
The only problem with that is.
S&W was case hardening hammers & triggers well before the 1920's.
Well before 1900 in fact.

They always case hardened hammers & triggers from the Model 1 forward to prevent any wear on sears and hammer notches.

The most noticeable addition I know of to combat Spanish forgeries was the addition of the Spanish 'Marcus Registradas' stamp on the lower right side of the frame.

Roy Jinks has noted that the company found it necessary following an infringement lawsuit in the 1920s to mark their exports to Spain with a Spanish-language trademark to protect their legal rights there.

The 'Marcus Registradas' stamp was resurrected after WWII when the four line address on the frame became standard.

rc
 
I just bought a 66-4 that has the stainless trigger and hammer

but......

have seen 66-4 that had case hardened instead.....?
 
To restate:

The first stainless steel revolvers were the S&W Model 60, followed closely by the Model 66.
For about the first two years these models had true stainless steel hammers and triggers.

S&W was not satisfied with the wear characteristics of these parts, so they changed to standard color case hardened hammers and trigger which were given a "flash" plating of hard chrome so the parts would better match the stainless of the rest of the gun, and to be more rust resistant.

In the early 1990's S&W stopped giving the hammer and trigger the flash plating as a cost savings and used ordinary color cased parts until the old style forged steel hammers and triggers were changed to MIM.

Flash plated hammers and triggers are recognized by the satin-flat gray color, versus the bright polish of the early true stainless parts.
 
The problem with case hardening, though, is it makes it impossible to do trigger jobs on older Smiths without compromising the parts' structural integrity. Once you cut through that thin surface layer, it will start having rapid wear. It's fine for people who use their guns as-is, but for those who want to tune them it's a major dealbreaker. Most of the older Smiths didn't exactly have the best triggers, either.
 
"Marcas Registradas" is Latin for "Registered Trademark."

"Marca Registrada" is Spanish for "Registered Trademark."

The phrase on the side of a Smith and Wesson is in Latin.
 
Most of the older Smiths didn't exactly have the best triggers, either.

Huh? All of my older Smiths have terrific single action triggers. They break clean and smooth with no creep at all.

I have heard the story about either patenting or trademarking Smith's case hardening process too. I have several of them from the 1920s and 1930s with REG U.S. PATENT OFF. stamped on the hammers and back of the triggers. I am pretty sure patenting or trademarking the process is what that was all about. I will ask around.

MPRoundButtHammer-1.jpg
 
I agree with Driftwood. Pre-numbered S&W triggers are spectacular. Of my roughly 30 odd 38/44's I don't have a single "bad" trigger in the bunch. All are smooth and crisp.
 
Pre-numbered, yes, but keep in mind that they kept using case hardening even after they started producing them with worse triggers. My M&P from 1954-1956 has an excellent trigger. My late grandfather's 10-5 has an awful one that's only made slightly better with a reduced power hammer spring.
 
Uhhhh....just picked up my Model 10-5 and dry fired a few times (with snap caps).

Think gramps must've got a bad'n cuz.

Just say'n.
 
1+ what dfariswheel said. Stainless steel, while very tough..is a "gummy" metal..never will get the glass-hard surface of a case-hardned steel..or the silky smooth/glass rod breaking feel of a classic S&W.
 
My late grandfather's 10-5 has an awful one that's only made slightly better with a reduced power hammer spring.

Howdy Again

Your original statement was 'Most of the older Smiths didn't exactly have the best triggers, either.'

I don't consider a 10-5 to be an older Smith.


*****

Just got an answer from the S&W Forum about the trademarking of the colors on S&W hammers and triggers.

"The trade mark consists of a mottled color pattern predominantly brownish-gray and blue applied to the hammer and trigger of the arm by an appropriate color process."

Trademark 207951, issued Jan. 12, 1926.

The document is printed in Neal & Jinks on one of the last unnumbered pages just before the Bibliography and Index.
 
Easily remedied by re-hardening the sear engagement surfaces.
Case hardening is specifically applied to steels that lack enough carbon to form martensite structures. When you case harden something, you introduce carbon to its surface (around .05" deep before final polish) then complete the hardening cycle. If you grind through the "hardness" you will not have enough carbon to harden the soft metal underneath.
 
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Case hardening is specifically done to steels that lack enough carbon to form martensite structures. When you case harden something, you introduce carbon to its surface (around .05" deep before final polish) then complete the hardening cycle. If you grind through the "hardness" you will not have enough carbon to harden the soft metal underneath.
Case hardening is done to modern steels to reduce wear on parts like hammers and triggers. Like I said, re-hardening the sear engagement surfaces is a common procedure.

Kasenit.
 
Case hardening is done to modern steels to reduce wear on parts like hammers and triggers. Like I said, re-hardening the sear engagement surfaces is a common procedure.

Kasenit.
Hardenability is not based on the vintage of steel, it's based on carbon content. Even common alloy steels such as 4140 cannot be fully hardened because they only contain .4% carbon and that is too little carbon to convert the entire steel structure into the hardened crystalline structure of martensite. This is the reason mild steel (.18% carbon) can hardly be hardened, medium carbon steels (around .3-.4% carbon) can be hardened into the mid-50's on the Rockwell Rc scale, and only high-carbon steels can be (almost) fully hardened into the high 60's Rc.

When a low-carbon steel (usually 1018 "mild steel") needs to be hardened, it is heated in a carbon-rich environment and held at temperature until the desired amount of carbon has "soaked" into the outer layer of steel. The steel is then quenched and only the outer surface has hardened, leaving the core soft and much less brittle. This hardening process is used when you want to begin with a cheap and easy-to-machine low-carbon steel and end up with a hard, impact-resistant part. Now please tell me why S&W would begin with an expensive and difficult-to-machine steel, heat-treat it with a very expensive process, to end up with a brittle part?

If gunsmith's are actually re-hardening these parts after substantial material removal, they are sending them out to be re-case-hardened. Flame hardening an alloy steel is something "easily" done in a machine shop, I've done it plenty of times. Case hardening cannot be done without a precision forge. I've tried it and ended up melting parts I've spent hours machining...

The details of this post are from memory and it's been a few years since my metallurgy classes, but the point is made.
 
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I know what case hardening is, as well as the role carbon content plays.


Now please tell me why S&W would begin with an expensive and difficult-to-machine steel, heat-treat it with a very expensive process, to end up with a brittle part?
Who said they do that???

S&W still case colors their hammers and triggers, even though color case hardening is not possible with MIM parts, because it is part of their trademark.


If gunsmith's are actually re-hardening these parts after substantial material removal, they are sending them out to be re-case-hardened.
No, for the third time, they re-harden the sear engagement surfaces, not the whole part.
 
If the steel begins as a low carbon steel (as the need for case hardening would indicate) then any re-hardening of exposed core steel would require case hardening. You simply CANNOT flame harden low carbon steel. A gunsmith can apply heat and quench, but that doesn't mean anything got hard. You state you know how case hardening works, but then you say "they reharden the sear engagement surfaces, not the whole part". Please tell me how they do this without re-case hardening if all the carbon-rich steel has been removed?
 
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