Retempering HSS drill bits

Discussion in 'Shop Talk' started by moopups, Aug 11, 2004.

  1. moopups

    moopups In Remembrance

    May 12, 2002
    In beautiful downtown Sticks, near Belleview, Fl.
    Scored a coffee can full of assorted bits at a yard sale but they have a blue hue indicating they were over heated via abuse. Is there a way to retemper them? What color should the metal be before cooling? Got 44 of them for $12.00, 5/8ths and down.
  2. kaji1

    kaji1 Member

    May 14, 2002
    My advice is cut the off at the discolored point and resharpen them.
    First they would have to be drawn abd then rehardened, a slow and long process done at controlled temps, and then you would have to contend with warpage. Not worth it.

  3. BrushBuster

    BrushBuster Well-Known Member

    Mar 30, 2004
    never done a drill bit before, but if i was going to try. i would take 1of them and normalize it then heat to different stages and try and when i got to a suitable hardness versus brittleness. i would normalize the rest, sharpen then temper to the same color. probably a blue on the cutting end gradually getting softer up the shank. you'll probably have some scale to contend with but that may be easier than having to reshape a hardened cutting edge. warpage could be a problem but if just for normal holes and nothing that has to be exact, it might not be to bad.