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Anneal the steel if needed. Are you using a known grade of steel or salvage? Carbon steel can be annealed in ashes or vermiculite if cooled slowly from cherry red. Then you can make the screwdriver and heat treat it from there. Heat treating entails heating the steel to around 1450-1600F and quenching in heavy oil. You can check the temp with a magnet. The steel will become non-magnetic once you reach the critical temp.
Don't gorget to draw the temper after hardening. I would draw the temper to a dark Straw or starting to just blue, then quench again.
Greg
 

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Isn't it also possible to grind at a low speed so the tip doesn't get too hot? This would not draw the existing temper.
 

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There is absolutely no need to anneal before grinding. Messing around with the heat treatment is asking for a problem. Just go slowly and keep the tips cool while grinding. If you can't touch it, cool it before proceeding.

WOB
 

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As WOB has stated, there is no reason to anneal a screwdriver to grind it, and why would you?. The chances of re-hardening it correctly are slim. Just becasue you brought it to the right hardening temperature, doesn't mean you will get the same results. Hardened tools are using put into a furnace and they stay in there for awhile, not just heating with a propane torch and quenching it in oil. You want a controlled heat.
The hardest thing with re-grinding a screwdriver by hand is to get the same thickness the whole length. It is hard to do hand held and to get the hollow ground area even for the depth.
 

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gr8day,

It is not necessary to mess with the heat treating.

The easiest way to hollow grind a screwdriver bit or blade is with a drill press. Get a wheel of the desired diameter that is mounted on a shaft. Harbor Freight sells them for reasonable price. Chuck it up and run the press on moderate speed.

Grab the screwdriver in a machinist's vise with the blade vertical. Adjust the table to the proper height. You can easily control the shaping of the bit this way. Keep a wet rag handy to cool the bit as necessary. When one side looks good, turn the blade 180 degrees and do the other side.
 

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Got to go with Curly on this one,

You over heat the tip and quench it, and your going to end up with a tip that is just too brittle and going to snap quickly. Plus trying to free hand the angle is going to end up with a mess anyway.

About the only tips that I make are for the Beretta receiver bottom screw since I cannot find one that wide and thin as an insert, and when making such, I so such on the mill so I can get the needed correct angle/unified tip, and fluid the tip so it does not get hot while being reground (diamond cut off wheel on an arbor, and not a end mill).
 

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I thought he needed one from scratch, not regrinding an existing one. Heat treating carbon steel is not difficult, a novice could get it right on the first try. Once you reach critical temp, and quench in oil it will be hard. Too hard to use, then you draw it using a torch and watching the temper colors. Any steel with .40% or more carbon will harden this way. Old round files could be made into screwdrivers if you had such a need.
If you really need one for heavy prying/twisting big screws, SAE 4140 would make a dandy screwdriver, and very tough.
Greg
 

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Robert, gun screws need to be hollow ground. A file will product a wedge shaped bit and it will not fit the slot properly and will slip out and bugger the screw head and the surrounding area if you are not careful.

Greg, you are right, it is not tough to do. When I grind mine on the small radius wheels they never get hot enough and the wheel will do the job.
 

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As CustomStox mentioned, just keep the steel cool if youa re regrinding. Some screwdrivers are harder than others and cannot be filed, but can be ground. It depends on the tools you have at your disposal. A nbench grinder or Belt sander is the best way. I keep a cup of cool water to quech the tool if the temper colors start to get beyond a dark brown. Dress the wheel son the grinder or use sharp belts too. The sharper the abrasive, the less heat buildup.
Greg
 

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Sorry Custom, but you can file that blade as flat as you want it and get a perfect fit for a specific screw slot. The reason you are altering the tool in the first place is to get rid of the taper. Just don't use an expensive screwdriver that is difficult to file. I've bought my last set of "Custom Gunsmith Screwdrivers". I've got a bunch of screwdrivers for specific jobs. Just don't mix them up with your "every day" tools.
 
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