Properly sharpening a drill bit certainly does take practice, and a very light
touch. In
the machinist's apprenticeship program I was in while in junior college, one of
the skills
the students were required to develop was hand-sharpening drill bits. The
instructor gave
each student three bits encompassing a range of sizes. We had to sharpen them
and drill a
hole with each of them in a block of mild steel. The instructor miked the
holes, and we
only passed if the hole miked out at no more than .003" over the nominal drill
size.
Better if you didn't have your morning coffee that day - shaky hands = bad
sharpening job!
Gary McCormick
San Jose, CA
Steve Harvey wrote:
> Hi Ronnie,
> My background is as a machinist and a cutting tool manufacturer's rep. Most
> of the hardware store/Sears drill bits are not that good. Even the top of the
> line bits sold at detail are less in quality then what a machine shop would
> buy. Better metal and grinding are the key. The way around that however is if
> you can hand sharpen your own drills. Keeping a lower quality bit shape is
> the answer. It takes time to develop the technique to properly shapen a drill
> bit. The standard angle is 118 degrees (included) or 59 degrees for each
> cutting edge. You can buy, or for that matter, I have a few drill bit angle
> templates left over from my sales days. I'll send you one if you give me your
> address. Just remember, you'll need a good flat dress on the grinding wheel
> and several old drills to practice with. I'd start with a big drill, 1/2"
> verses a 1/8" to practice with.
> Good luck
> Steve Harvey
> Milwaukee (COLD)
>
> Ronnie Day wrote:
>
> > Okay,
> >
> > Since it's the weekend and some of the group at Doheny I thought I'd
> > throw this question out. Where you folks get your drill bits, and do you
> > sharpen them or just replace them? It seems like either the bits that I
> > use are either dull or cheap cast pieces that snap if you look at them
> > crooked.
> >
> > You can get bit sharpeners, I think, and I've seen jigs that are designed
> > to be used with a bench grinder. Does the Sears Craftsman lifetime
> > garamtee cover drill bits, too?
> >
> > Later, Ron
> >
> > Ronnie Day
> > ronday@home.com
> > ------------------
> > Dallas/Ft. Worth
> > ------------------
> > '71 510 2-dr (Prepared Class Autocrosser)
> > '73 510 2-dr (Street Toy)
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