doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Shooting Fox with annealed frame?

pa24, you're wrong on that. beginning with intro in 1912, 16 and 20 bore receivers were mostly chromox with a few carbon steel here and there. also, carbon steel for 12 gauge receivers was phased out after 1912 and within a few years they all were made of chromox too.

first poster with the question was bbman. what say the site experts? what's he supposed to do now if his annealed receiver is chromox steel but with unknown % of alloying elements?

I have owned a good many Foxes over the years and some have Chromox frames as they turn a bright nickel finish when case colors wear off.A good many have or had a duller gray finish and hardly if any shine.Have no idea what type steel they are.A Chromox frame has brighter case colors in my opinion.I have no idea which is best. I plan to have no engraving at all on the frame,even filed off Sterlingworth.Maybe i ought to leave it as is and not have frame hardened.It should be easy to bend frame back if it does get off face? Thanks for all the response. Bobby

Do any of the Fox records correlate serial # with action alloy? Do Fox records indicate the exact alloy of "chromox"? Do Fox records indicate the heat treat processes used?

Why would Fox use "chromox" for actions? Barrels are not heat treated. So, why use a heat treat alloy for unheat treated barrels? Or, did they use "chromox" for actions exactly because it didn't need a heat treat?

I don't know what "Chromox" is but I suspect it's an early chromoly steel.

On the frames wearing to a bright "nickel" finish as an indicator of the alloy being chromox, it brings to mind LC Smiths. All LC smiths I've had wore to a bright nickel like finish, but all were case hardened low carbon steel as well.

I believe if you case harden, harden being important, you had to do the exact same fundamental metallurgical process. Carbon alone in iron will not harden unless its arranged as martensite. I don't believe its possible to 'case harden' and 'heat treat' as two separate procedures on the same low carbon receiver using charcoal pack and water quench.

I suppose heat treatment is generally thought of as hardening, but I guess steel might be treated with heat for results other than hardening. I'm still not sure though what process or goal of 'heat treating' the core of a low carbon steel receiver would be.

fox advertised chromox as chrome nickel vanadium alloy steel but i've never seen the percentages quoted. those who own fox guns should be proud to know fox was way ahead of competing makers in using alloy steel starting 1912 with the 16 and 20 gauge guns. that was years before winchester did the same with its m21. those interested in the winchester's comparison of its alloy steel, properly heat treated, and the same steel case hardened, should refer to that testing in schwand's 21 book. suffice to say the heat treated alloy was way stronger than the same steel, case hardened. now back to bbman's dilemna. he probably has a chromox small gauge receiver, what's he to do now that its annealed? what say our resident metallurgists and mech e's?

Nitro,
Since the Fox continued to be casehardened, even thru the Savage years, I suspect the alloyed steel you describe for the frames did not contain high carbon content and therefore continued to be casehardened.

Note that "Steel" is itself an alloy of iron & carbon. What we normally refer to as "Alloy Steels" means they have some other alloying component than carbon. Most, but not all, alloy steels have a high enough carbon content to allow through hardening. There are some low carbon alloy steels produced specifically for case hardening purposes. As the fox Chromox frames were "Case Hardened" as I understnd it I can only assume they were of too low a carbon content for through hardening, The M21's frame was a higher carbon frame suitable for through hardening. Thus while both are "Alloy Steels" they are not identical in terms of treatment. As to strength if one looks at the charts of various steels giving their strengths they will be hard put to find a heatreated alloy steel which is not stronger than a case hardened mild steel. That said though when the requirements are met with an adequate safety margin, there is little "Real Gain" acheived from a practical standpoint.
As to terminology "Heat Treat" is not a specific process. The hardening portion of case hardening is to quench from a temp above critical temp, same as on through hardening steels. While true the hardening cannot be accomplished seperate from "Heat Treating" the carburizing process can, & sometimes is, done as a seperate operation. In this process the part is brought up to heat & held for the required time in the carbon rich atmosphere & then allowed to cool slowly. The Carbon Case is thus acheived, but it is not hardened. Following this the part is then "Heat Treted" IE brought up to temp & quenched. Unles there is some specific need to do so both operations are ordinarily combined, IE the part is quenched directly from the carburizing step, even so it is basically a two-step operation. It differs from the heat treating process of a through hardening steel only in the first or carburizing step.

Ned Schwing's book on the Model 21 and his discussion of the steel used in Model 21 frame manufactrugin has nothing to do with Fox shotguns. The Chromox and Krupp steels referred to in Fox manufacturing were for the barrels and not the frame. Winchester specifciations for the Model 21 and Fox specifications have nothing to do with each other.
Fox recievers continued to be of mild steel and required case hardening while Winchster recievers were manufactured of high tensile steel requiring no surface (case) hardening which resulted in Winchester recievers being blued and Fox case hardened.
I could not find my copy of McIntosh's bok on the Fox but I don't remember ever having read documented results for receiver steel used.-Dick

�Vanadium itself, when combined with steel very low in carbon, is not so noticeably beneficial as in the same carbon steel higher in manganese, but if a small quantity of chromiumis added, then the vanadium has a very marked effect in increasing the impact strength of the alloy.....Chrome-vanadium steels also are highly favored for case hardening. When used under alternating stresses it appears to have superior
endurance.�

Have a nice day

Mike