[TheForge] Re: drill bit stock

[Mike Spencer]

> Does anyone out there know the type of stock used in the common
> hardware store high speed drill bits for steel.  Do you per chance
> know the steps for annealing them.
>
> Yes,  I ask because I broke a drill bit in a piece of stock....

Somewhat tangential to your question, but IIRC, concentrated nitric
acid dissolves drills faster than it does m/s.

If I was stumped and the hole were, say, 1/4" or bigger, I'd try this:

  1.    Flush the hole with hot soapy water (only if there's oil
        lubricant in it.)  Blow out with compressed air if you have
        it.

  2.    Add a few drops of concentrated nitric acid with an eyedropper.

  3.    After the fizzling slows, flush with clean water, dab dry with a
        paper towel. (NOT NOT NOT blow dry with compresed air --
        splatter, don't you now?)

  4.    Repeat 2. and 3. until the broken bit can be extracted
        somehow.

Face shield and (rubber?) gloves -- possible spatter.

Good ventilation.

A quart of baking soda solution (in water) nearby to neutralize any
spatter or spills.

- Mike

-- 
Michael Spencer                  Nova Scotia, Canada       .~. 
                                                           /V\ 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^

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