Hardening mild steel???

K

KenH

Well-Known Member
This is a bit off topic for knifemaking, but there are some VERY knowledgeable folks in the group. I just made a trigger for a Rolling Block rifle from a bit of mild steel - perhaps 1018 or so. It needs to be hardened, or at least the sear tip to prevent wear. My idea is to quench in brine solution - no harder than mild steel will get, is there any reason to temper after?

Perhaps the best idea would be to case harden using something like kasenit?

Thanks for any ideas or info.

Ken H>
 
Well, heating to 1550ºF then quenching in "super Quench" didn't do much - straight out of quench tests at 15Rc. Before HT the 1080 tested at the "90" on the Rc scale below zero so the steel did pick up some hardness - not sure it's as much as I want for a trigger sear. This trigger was more of a prototype, so next step is to use some high carbon steel. I've got some 1080 I can use - I'll have to forge a bit on it to get it thick enough. My 1080 is 1/4" thick and I need .309" finished thickness at the pin point.

Anyway - that's what's going on in my shop today {g}

Ken H>
 
Hi Ken!

Using "mild" steel/1018 is going to be a battle for the application you mentioned. Probably the best advice I could offer IF you must use 1018 is to case harden it. Even that won't be a long term solution, depending on how much use the part sees.

Personally, the triggers I have made for folks tend to be of 4140, or 1045. 4140 uses the traditional heat treat of quench, temper, and for the 1045 pieces I leave them as quenched. I tend to lean towards the 4140 for "modern" firearms, and the 1045 gets used on "period" type firearms (flintlocks and muzzleloaders).
 
Thanks Ed - I value your opinion. I'd sorta come to a similar conclusion myself but wanted to get some confirmation. I'd forgot I had an old railroad spike I could have used - that should be around 1030 to 1040 depending on type of spike. While it won't harden really hard, it just might get hard enough with "super quench" - "IF" that stuff is half what it's fabled to be {g}

The 1018 is all I had that was correct thickness so I decided to practice with that. The trigger turned out as good as I'd wish, so now it's to build a permanent trigger. What do you think of the 1080? I've got that, and while it's about .050" thin, I could use a .025" brass/copper washer on each side to take up the slack on the trigger pin.

This isn't a rifle that's going to shoot thousands of rounds, but still want a good trigger installed. Now I've got the "soft" 1018 at Rc 15 I can shoot some while getting correct metal, so no rush.

Ken H>
 
Yep Raymond - that's the stuff I referred to in first post - or I think the Cherry Red is about the same as the Kasenit. I've thought about trying to carbonize the sear edge with a vibrating etching using a tungsten tip. Sounds easy to do, just have not played with that yet. Sure would make a hard edge - "IF" it worked {g}

Ken
 
I have used kasenite many times. It goes on great and seems to wear just as well. It seems to me I heated the area red and then covered it by sort of rolling it in the kasenite. I would repeat this several times. Yes, this was for a sear and the gun was shot hundreds of times afterward without showing any wear.
Frank
 
Thanks for the info Frank - I just might have to order a can of kasenite, just wish they had about 1/4 can for $10 {g} Even that would do severa; sears/

Ken H>
 
No finishing work required is pretty important when talking about a sear. those things need to be polished and setup to have a good trigger. After case hardening it would be hard to smooth out, especially without going to the surface case hardening.

Good to know - thanks.

Ken H>
 
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