drill bits

[cool_arrow]

I've recently had to drill many holes through 1/8" stainless steel and realized that most of my drill bits, while ok for wood, are dull and don't cut metal well. Years ago people would send their drill bits to be resharpened. Do people still re-sharpen bits or is it cheaper to just buy new ones these days?

[bigtomrodney]

It's definitely cheaper to buy new ones. I find when buying drill bits you're better spending a little extra on them, except with masonry bits. Obviously don't buy crap masonry bits, but even with really good ones it can only take that one minute of pushing too hard to destroy them.

To be fair you can buy a set of 150 Titanium or Tungsten Carbides for probably €30-40. I'd expect that to pretty much equate to dollars.

[cool_arrow]

I suspected that buying new ones was the way to go these days as so many bits are carbide tipped now. I think stainless tends to screw them up pretty fast as it is a relatively poor thermal conductor and the bit heats up much faster than when drilling cold rolled steel etc.

[oz]

I've always sharpened my drill bits myself. With the proper tools and proper angles on the bits they've worked fine.

[rcgreen]

Stainless requires a harder bit than the normal type.
See if you can find cobalt steel bits.

[MikeTbob]

Stainless requires a harder bit than the normal type.
See if you can find cobalt steel bits.

Amen, and some cutting fluid wouldn't hurt.
Who woulda thunk we got drill bit masters on a Linux forum.

[d38dm8nw81k1ng]

don't forget to keep a spare set. it's irritating when you're drilling through a wall and have to blast off to wickes halfway through because your drill bit broke.

[carlosponti]

trick is to keep it cool while you are drilling. heat will almost certainly ruin bits. get some cutting oil to reduce the temp. My dad was a machinist for general motors and i learned a few things from him. Look up harbor freight in your area since you are in California they have great prices on drill bits and such. might find some cutting oil there too.

[fingal]

The last time I drilled anything it was through a partition wall with a tiny drill. Must say this is the first really original thread I've seen in a very long time. Well okay, the second.

[cousinlucky]

When I was going through my machinist apprenticeship at the Quincy Mass. shipyard I was kept in the tool room for a very long time because I was the only apprentice that could catch on to old man " Harold's " technique for hand sharpening drill bits. I do not know if I can adequately describe how to do it with just words. First you have to have a metal scale to make sure that both edges are of equal length when you finish. There are two hand motions that must be done simultaneously while the drill bit is lightly pressed against the grinding wheel. You have to lift the drill bit on the wheel towards your head while rotating it clockwise. If you are going to drill brass you also have to flatten the lips of the drill otherwise the drill will break because it will dig in too fast and jam.

If you are going to drill something hard, use a drill that is carbide tipped. Carbide tipped drills cost a lot more than regular drills but they can last you a lifetime. If you do a lot of drilling carbide tipped drills are the way to go.

The guy sharpening drill bits correctly is a rare thing in my neck of the world. I hear quite a few horror stories about high cost and poor workmanship all of the time.