doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com A curious Ithaca 100

Miller,
I'm not so sure it's a faux case coloring. I recall seeing a 4140 frame that was colorcased by a respected outfit that looked very similar.

Miller,

Would you expand on alloy steel and bone/charcoal CC being problematic. Too much carbon?

Chief

Chief;
Yes, case hardenimg is almost universally done only on low carbon steels where a soft core with a hard skin is desirable. When the carbon content of a piece of steel reaches about 30 points (.3%) the part will through harden. It is normally heated & quenched which puts it in its maximum hardness condition & the re-heated to a lesser temperature to "Draw" the temper to its desired condition. Case-hardened parts on the other hand have their case left in virtual maximum hardness, with the core remaining soft as it did not harden. When the higher carbon steel is left in the max hardness condition it will then be too brittle & subject to cracking.
The coloring process as I understand it will work below the hardening temp so that an alloy part could be colored only, but also be aware this will leave the part basically in its annealed condition with most all of its hardness having been drawn out. I do not really know to what temp the makers of alloy steel frames draw their frames, but highly suspect they do impart some degree of hardness to them.
Any work of this nature should definitely be entrusted to someone who knows a lot more about it than I do.
The work on the gun in question does appear to be professional quality, so most likely was properly done.

Miller,

Thanks, something to consider. If the gun was taken apart could the inside of the frame be tested in a hidden location?

Chief

Miller,
Dr. Gaddy recommended Doug Turnbull for color caseing martensitic steel framed guns. Also, there's a gunsmith named Bachelder that does traditional case colors on Parker Repros, although I'm not sure if he does the process or sends it out.

On martensitic steels being too hard at their max hardness, I would agree when discussing gun frames. However, there are alloys that have high shock resistance at very high hardness. With the RBL guns, CSM chose to machine them in their ready to use hardness, which I believe was in the mid thirties RC, not all that hard to machine and still at traditional modern gun hardness.

I usually skip over these 'esoteric' discussions regarding the science of steel, hardening, annealling and so forth. You guys are way smarter than me. It occurs to me though that Ithaca produced its lower priced offerings with 'malleable(sp?) steel' which I take to be unhardened. How important is the case hardening process anyway?...Geo

George,
I don't have any specific SKB/Ithaca info, but "mallable steel" could infer about anything this side of "half hard".

Nicely done. I picked up a Beretta Silver Hawk that some one had restocked. If I had seen this SKB I would have not have been able to pass it by. Just goes to show, that some "projects" will never return the money invested.

Pete

To my knowledge, the only Ithaca doubles made with malleable iron were the Western Arms guns. I'm sure Walter could correct or verify that. And as far as I've heard, those frames proved to be pretty durable.

Yes Larry, it was the Western Arms line I was referring to. I don't believe the frames were hardened at all...Geo