doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Screwdriver question...

SGSP - the operative word was "Stanley"; ie. high quality steel shanks with good heat treat. Your plan is a good one if: you learn good handworking skills; have a good way to gring precision size and shape; learn to identify differing steel alloys and levels of heat treat; learn to do small parts heat treatment; develop a good dose of patience; and do your learing on something cheap.

Grind to fit is the only way to go. Whether it’s a cheap screwdriver or an expensive screwdriver, it’s still cheaper than the gun you’re working on. If you have a grinder, good stock to work with can be found all over the place. I routinely pick up spare magnetic tips at hardware stores for less than .50 and then keep them on hand for when I need to grind to fit. I don’t worry too much about it being too hard or two soft because I’m very careful when I have screwdriver in my hand (except when it’s a home improvement project; in that case, I’m just plain dangerous).

Like the carpenter’s old saying, “Measure twice and cut once.” I always prep anything that’s about to receive a screwdriver. I clear the bench to make ample room, check for anything underneath that will scratch. I always position myself where I have a good view at what I’m doing and I try to be directly over the driver whenever possible. Lastly, I take it easy and if it’s not working, I look for alternative ways before throwing more muscle at the problem.

I plan on only getting good ones. I have a bench grinder, and I am pretty handy. How does one go about iding different alloys and levels of heat treatment? How do you do small part heat treatment?

Alex

Perhaps to avoid a lot of trouble and undue expense, you might want to consider laying in a stock of round stock tool steel. It is many times better to know what your material is to do your grinding, send out at one time to have the heat treat done. Handle material is readily available. Just an idea.

Mostly beyond the scope of this board, but start with file test of steel and with grinder sparking test. Look these up in reference material and if you can't find anything, I'll check for some reference works. Heat treating small parts with a torch is simple in principle, but requires some skill and learning in practice. Basically you heat the part above the steel alloy's critical temperature and quench in a bath designed to cool at a rate compatable with the alloy's hardeneing characteristics. Then, you may well temper by reheating to a lower temperature. The glow color of the steel is a indicator of temperature for hardening and the oxide colors for temper. This is easier if you have access to a heat treating oven, but you most likely don't. Again read some reference works on doing it by hand in a small shop. Craftsmen have been doing this for a long time, so it can be done.

I agree with Rocketman. The file test is a good one, if the file slides across the steel then it is close to being as hard as the file. Probably Rockwell 60-62. For a screwdriver I think that is too hard, easy to break the tip and damage surface.
In making your own, getting the right steel is critical. To do the job right you should have an oven like Rocketman said. On small parts you can use a oxygen/acetelyne torch with the piece sitting on a scarp piece of steel on a fire brick and carefully heat the steel to cherry red (2500F) and quench in used motor oil (if it is oil hardening tool steel), clean carbon from piece by sanding and it should be a moltted greyish color. Re-heat to a light straw color (1250-1350F) and quench again. Try the file test and see if it "bites" into the steel, if ok then grind to fit screw.
Without an oven trying to heat treat long (4"-6") pieces you will warp them using a torch, you need a controlled heat and to bring the temperatuare up gradually. The torch does it in seconds and would warp a long piece.
Good luck in what you try, but the best way in my opinion is to buy cheap screwdrivers with some temper and grind them to fit.

light straw is way less than 1250 degrees....things get cherry around 1500....with out looking...straw is less than 700 degrees f.
To keep things simple for yourself Storm, just buy good ones and dont over heat them.
Steve

I stand corrected on the temperatures. This is what happens when you try and remember things from years ago. Anyway I looked up tempertures of plain carbon steel and this is by using your eyes as an idicator.
1075 deg.F Red heat visible in sunlight.
1290 Dark red
1470 Dull cherry red
1650 Cherry red
1830 Bright cherry red
higher than 2200 deg.F is starting to get white and telling temperatures is not possible with the naked eye.

Tempering temperature of plain carbon steel by color:
430 deg.F very pale yellow
440 light yellow
450 pale straw-yellow
460 straw yellow
470 deep straw yellow
480 dark yellow

I also agree with Steve to buy screwdrivers and grind them.

Did you guys ever read the late JULIAN S. HATCHER's NOTEBOOK?

Using color vision for heat treating is a mistake, gang.

Just ask several hundred thousand Springfield 1903 receivers.

It's very difficult to beat a Stanley...they combine pratically the best tool steel with proper heat treatment, to a large diameter triangular shaped handle. The larger diameter handle allows the operator to deliver more torque than with a conventional round handle of smaller diameter. The Stanley screw drivers below are my favorite. When you're garage saling/sailing, these are the ones to watch for (and Winchester, but you don't grind them)

When hollow grinding. quench often and try not to disturb the factory temper...in fact quench too often