Dumb Question about Case Hardened Hammers and Triggers

[Driftwood Johnson]

Howdy

I suspect I already know the answer to this question, but I just want to make sure.

Did S&W ALWAYS case harden their hammers and triggers? I know if you have a hand ejector and the hammer and trigger are either blued or nickel plated, it is a dead giveaway that the gun has been refinished. I also have four nickel plated top breaks, and they all have at least some case hardening showing on their hammers and triggers. But when I bought my DA 44 a few months ago, it did not even occur to me to mention that the hammer and trigger are blued. I have no doubt the gun has been refinished, for a few other reasons. I just want to know, have hammers and triggers always been case hardened?

At least regarding top breaks and hand ejectors?

Thanks

 

[H Richard]

To my knowledge, including the early single action's.

 

[Ballarat]

As above, I believe so.

 

[Will Carry]

I think I read somewhere, maybe here, that Smith and Wesson do not case harden the hammer and triggers any more. I'm not sure when they stopped.

 

[murphydog]

I think I read somewhere, maybe here, that Smith and Wesson do not case harden the hammer and triggers any more. I'm not sure when they stopped.

I think the revolver hammers and triggers are still case-hardened; the MIM composition makes the colors less bright. The plastic M & P autos are not .

 

[scooter123]

The newer MIM hammers and triggers are basically through hardened as a consequence of how they are made. During certain periods of production of the stainless steel revolvers had hammers and triggers that were case hardened and then flash chrome plated so they would match the appearance of the stainless frame and provide a bit of protection against corrosion. That pretty well covers the recent production since about 1965.

As for the antiques such as the top breaks and early hand ejectors, I'm certain that they all had hammers and triggers that were flame hardened. If they weren't hardened I don't think the single action sear would have lasted for more that 100 shots. However, the appearance of the flame hardening was not considered as special feature to be sought for, so it was probably quite subtle on most guns.

 

[Oyeboteb]

Some clearification of terms -

'Flame Hardening' is something dfone to Bamboo or Wood, in contexts of making simple Spears or Arrows which will have no tips of other material.

'Case Hardening' is what is done to some kinds of Steels for attaining a high degree of surface hardness and hardness to some depth, while retaining an interior which is not as hard, and, which will then remain tough and resillient, and thus allows the part or component as a whole, to stand up to shock without shattering.

Case Hardening is done in a sealed Vessel, in a heavy reduction Atmosphere, using a container which holds sources of Carbon and often other elements as well, and which excludes Oxygen, and, the process is not done with any Flames as such...but rather, in one way or another, is done by Baking.

 

[scooter123]

Some clearification of terms -

'Flame Hardening' is something dfone to Bamboo or Wood, in contexts of making simple Spears or Arrows which will have no tips of other material.

'Case Hardening' is what is done to some kinds of Steels for attaining a high degree of surface hardness and hardness to some depth, while retaining an interior which is not as hard, and, which will then remain tough and resillient, and thus allows the part or component as a whole, to stand up to shock without shattering.

Case Hardening is done in a sealed Vessel, in a heavy reduction Atmosphere, using a container which holds sources of Carbon and often other elements as well, and which excludes Oxygen, and, the process is not done with any Flames as such...but rather, in one way or another, is done by Baking.

Actually you are a bit short of the mark. There are many grades of steel that can be hardened by heating with a torch and then letting the part air cool. It happens that 8620 steel is one of these grades and we have ID punch arbor for punching holes in a 24 inch long 1 inch square tube that is made from 8620. In that application it's not possible to use hardened inserts without weaking the arbor. So, we made it using 8620 and had a local heat treat house flame harden the areas where the holes are punched. As a result we have an arbor that is quite high in toughness but also has critical areas hardened so that the cutting edges stay sharp. Currently that job has been running 800 parts a day since 2005 and we've only used 3 sets of arbors.

Bottomline, if the carbon content in the steel is high enough, it's a rather simple process to flame harden it. However, it's also a distinctly a matter of skill, so if we need something flame hardened we send it to a Pro.

 

[Oyeboteb]

Actually you are a bit short of the mark. There are many grades of steel that can be hardened by heating with a torch and then letting the part air cool. It happens that 8620 steel is one of these grades and we have ID punch arbor for punching holes in a 24 inch long 1 inch square tube that is made from 8620. In that application it's not possible to use hardened inserts without weaking the arbor. So, we made it using 8620 and had a local heat treat house flame harden the areas where the holes are punched. As a result we have an arbor that is quite high in toughness but also has critical areas hardened so that the cutting edges stay sharp. Currently that job has been running 800 parts a day since 2005 and we've only used 3 sets of arbors.

Bottomline, if the carbon content in the steel is high enough, it's a rather simple process to flame harden it. However, it's also a distinctly a matter of skill, so if we need something flame hardened we send it to a Pro.

The question was not about Hardening, but, was about Case Hardening.

The colors associated with Case Hardening are not acheived by wafting the Steel parts in a 'Flame'.

Yes, of course, one can heat various Steels by any means one likes, including an Oxy-Acetylene 'Flame'.

This will not result in 'Case Hardening' nor will it necessarily result in anything like 'Case Hardening Colors'...though colors of a generally similar sort can be acheived by any means of heating, so long as the temperature does not get beyond the range at which those colors occur.

Heating Steel in a Flame will not necessarily result in any 'Hardening' of the Steel at all, if all one did was to Heat it in a 'Flame', unless it is an Air Hardening Steel which is an entirely different matter from Traditional Steels which require to be brought to a certain and even Heat, and, then Quenched, thereafter to be Tempered.

'Heat Treating' tells us nothing of what was done to a Steel, other than, I suppose, someone 'Heated' it, and, that the real details were lost or never part of the story about it one may get.



I was not off any 'mark'.

I was discussing Case Hardening...and, Case Hardening has nothing to do with heating Steel in 'Flames'.


The only context I have ever heard or read the term 'Flame Hardening' occur, is in regard to Wood or Bamboo.

I have never come across the term in relation to any process involving Steel unless it was in an entirely naive or uninformed use.

Nor would any Traditional Steels 'harden' for merely being Heated in-a-Flame, anyway.

If anything, this will Anneal them, rather than to Harden them, or depending on the temperature reached, and, the rate of cooling, there-after.

Tempered Steels which have gone through House Fires or similar, do not become Harder, they become Softer...they get 'Annealed' by the process of the 'Flames'.

Possibly, your Arbor was 'Case Hardened'.

Or, Hardened and Quenched and left Hard, or, Hardened and Quenched and then Tempered by heating again to a lesser Heat, and, then Quenching at the correct temperature.

There is no such thing as 'Flame Hardened' unless one is speaking of Wood or Bamboo.

 

[scooter123]

I assure that they were indeed flame hardened. Back when I was a co-op student in Mechanical Engineering I worked at NRM (National Rubber Machinery) in Tallmage, Ohio. One of my tasks was to produce detail drawings for the feed screws on their extrusion machines and one aspect of these feed screws was that many had the outer surfaces of the flutes flame hardened. They had 3 employees in the Build Shop who did this and they were the highest paid workers in the Build Shop. BTW, another process for hardening this critical area was by the application of Stellite 156 using a flame sputtering process, however that process required a re-grind operation after the Stellite application and most customers didn't want to pay for the added cost.

I'll grant that it's not actually a case hardening process, however it is a viable process for hardening key areas. It will also produce coloration effects somewhat similar to the case colors seen on some vintages of revolvers, however my experience is that the rainbow hues evidenced in these parts are an indication of inferior technique. When we get our arbors back from the heat treat house that offers this service, the bluing in the flame hardened area is very even and also very evident. It's also an excellent method for obtaining a tool that is ductile in the bulk of the material so that it won't suffer brittle failure while having critical areas at full hardness.

BTW, we chose this method based on prior experience. One problem with case hardening is that the case can tend to crack of the tool is "flexed" and once cracked, those cracks spread. While it is possible to mask a case hardened part during the carburizing process, this does cost more for large components and most carburizing steels don't have the balance of strength and ductility that a steel such as 8620 offers.

 

[rhmc24]

All this makes me chime in. I am writing about simple carbon steel, which is iron with only carbon added. Other and most modern steels also have some content of other metals in them such as chromium, molybdenum, etc. to enhance specific functions.

Case hardening is usually done to low carbon steels to make it hard on the outside when the carbon content of the steel is not sufficient or not wanted to harden throughout. I do it in my home shop using a product called Kasenit. I heat the part to red, push it into the Kasenit powder, take it out and keep it red for half a minute or so, letting the powder 'cook' and bubble, then quench it in water.

The 'cased' exterior is glass hard and the inside condition depends on how much carbon is in its steel. Obviously, if you case harden higher carbon steel, the interior will be glass hard too with probable brittleness.

Carbon content determines what kind of heat treatment can be effective. Any carbon steel can be hardened somewhat by heating red hot and quenching in water. This hardness can give strength and can cause brittleness. Up to a practical point, the more carbon, the more the steel reacts to heating and quenching.

Higher carbon steels are used to make springs, chisels, punches, etc. If you want to make a spring, you can often find suitable steel from old carpenter saws, carbon kitchen knives, files, etc. To make a spring you first anneal (soften) the steel by heating red and allow to cool slowly, not quenched. You then make your spring, fit and shape it, then heat and quench it. It is now hard as glass and brittle. So to "temper", I put my hard spring in a metal dish in a half teaspooon of motor oil, heat it from below till the oil catches fire and burns off. Allowed to cool in air, I have my spring. I have tempered springs in the kitchen oven by turning up to max to get the 560F degrees, watching/knowing that its temper is right when it turn deep blue.

If you want to make a tool needing hardness, like a scraper or chisel, you want to polish it after quenching, then slowly heat it till it just begins to turn to a very light brown, let cool in air. Higher temp gives color changes as it changes to spring temp. Further heating softens the temper. It is worth while to note that higher carbon steels such as SAE 1095 (clock spring steel) should be quenched in oil rather than water.

Note to scientists and academics--- I tried to write something here that the ordinary person can use with a little experimentation and care. I have some experience in that I have done the above scores of times over the past half century. Unfortunately space does not allow a lot of useful detail.

 

[Driftwood Johnson]

Howdy Boys

Well, I certainly did not mean to start a range war.

Yes, when I posed the original question I did specify Case Hardening. The old fashioned method of hardening the surface of low carbon steel by infusing a little bit of extra carbon into the surface.

And yes, I was referring to antiques - Top Breaks and Tip Ups. Looks like I got my answer.

Thanks

 

[handejector]

DJ,
To answer your question-
Yes, the forged hammers and triggers on top breaks and hand ejectors were always case hardened in the traditional charcoal process.
Naturally, with S&W, we can cite an EXCEPTION- at least one Reg Mag in nickel was ordered with a nickel hammer and trigger, and the factory did it!
___________________________________________
On another note, why would any data about MIM parts be provided in this ANTIQUE section?

Why would an argument start about any hardening process besides case hardening to answer a question about case hardening?

Just curious- is there nothing on TV today?