This is an 11/16" drill that started life as a tapered shank drill which had been turned down to 5/16" shank. The shank eventually ended up all "chewed" up. I decided to salvage it. I turned the shank down to 15/64" I then made a steel sleeve to close fit slip on. The hole goes all the way through the sleeve and the sleeve is about 2mm longer than the shank.
With sleeve slipped on you can see the chamfers meeting.
Shank Nickel-bronze brazed to steel sleeve. I also brazed the hole in the end.
Scrap steel jig drilled to 9/16" through and then drilled and tapped 1/4" UNC for socket head cap screw.
Jig reset in chuck and finish bored so drill will be a neat fit.
Drill installed in jig and shank turned down to about 1/2" Dia.
Repaired drill dialled up to .004" TIR.
Proof's in the puddin they say. Works fine. I'm glad I fixed it now and not just thrown it out.
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