Case hardening depth on S&W hammers and triggers

[Troystat]

I have a 17-4 that I have owned for 40 years, shortly after I got it I had a well regarded gunsmith do an action job on it, in addition to cleaning up the action, doing a trigger job, polishing or reaming the cylinders he also polished the sides of the trigger and hammer which removed the case hardening colors. I have probably put 10-15 thousand rounds through it and have not noticed any issues. My question is how deep is the hardening on the trigger and hammer or is the case hardening only decorative in this era gun.

 

[robertrwalsh]

As I remember case hardening is actually very shallow. I don't recall HOW shallow but it ain't much.

 

[STCM(SW)]

That's way sometimes MIM parts are better.

 

[chief38]

My understanding is 0.003" to 0.005" but that would just be repeating what I have heard by a S&W employee 30+ years ago - not by my own personal testing.

 

[2152hq]

Chiefs approximation is about right.
It does vary as the orig process that it is done by doesn't have pin point control over depth on surfaces of parts that have odd contours.

 

[kev74]

The case hardening goes deeper than the color. So if the color is removed, the part will still retain hardness.

The sides of the hammer and trigger being hardened have little to no impact on the durability of the gun. Only the engagement and bearing surfaces really matter.

 

[03hemi]

Yeah it's not much, as stated, it's only 1000"s of an inch.

 

[halfmoonclip]

Never did get a reliable answer, as regards the through hardness of MIM parts. Subjectively, the older, forged parts seem to slick up more readily.
I've been slicking Smith actions forever, never had an action job 'wear out'.
Moon