All About Pocket Knives

Hi,
Just wondering if anyone has made a new lockback backspring/lockbar?
I came accross some LB7 frames, but they are missing the spine and butt spacer/spring keeper.

or does anyone know of a company that could make new ones for a reasonable cost?

Snorkel-
I just knocked apart an LB-7 to take a look. It looks to me like you could make the lockbar out of a piece of flat stock, just cut it to shape and heat treat. I'd probably use O-1 because I have a few flats of the correct approximate thickness. Just cut/file/fit to shape, DRILL, and temper. Out of habit I'd probably use a spring temper.

You could use the same stock or something of the same thickness for the spacer/spring keeper. If you used O-1, I'm not even sure you'd need to heat treat this piece though it wouldn't hurt. Piano-wire for the spring, and Bob's your uncle.

At least on the one I looked at.

You'd have the advantage of not having to re-work that dang 2-piece flat spring found on later knives.
Jim

Do you think it could be heat treated with just a propane torch? As that is all I have

I would think the whole thing would not need to be heat treated, just the drilled pin hole area the the end that locks with the blade.

snorkel wrote:Do you think it could be heat treated with just a propane torch? As that is all I have

I would think the whole thing would not need to be heat treated, just the drilled pin hole area the the end that locks with the blade.

Think of it this way: break "heat treatment" down to "harden" and "anneal."

I've not tried to harden something this size/shape with a propane torch, but I've done it using a propane forge. The torch might work--if it gets close you could use a couple of fire bricks to redirect the heat, or build a quick fire pot and use that.

I know you can harden and temper something this size with a gas stove, did it when I was about ten years old. (Got grounded for a couple weeks, but that was OK.) You could also do a trade with someone who does oxy-acetylene welding. Worst case, you can get it hot enough with a charcoal grill, with maybe an improvised bellows to increase the rate of charcoal burn.

Once it is hardened, it gets easier. As long as you stick with simple steels (O-1, W-1, etc), you can anneal with a variety of low-dollar techniques: flash off oil, molten lead, cheap electric stove, etc. If you want to use the torch for it, get some of those

For something like this, if you've not worked with heat treatment before you are probably better off doing the HT on the whole thing. Trying to spot-harden is a bit more likely to warp the piece you are making.

While you are figuring things out, you might want to get some temperature crayons, like Temilstiks, to give you a better idea of the temps you are reaching.

Good luck!
Jim