Drill Bits

TomNativeNewYorker · Post by **TomNativeNewYorker** » Sat Apr 15, 2006 7:39 pm

At my job, we have to supply our own tools and drill bits.

Drill bits can get costly when you need to have a diverse amount of different sizes. Sometime when pulling special inspections on a bird we may have a large amount of screws needing drilled and easy out and screws can eat up sharp bits quick.

The more common sizes such as #40,#30,#27,#21 and #11 I usually buy by the dozen from Grainger which I have found to be the best value around and I can stop in on the way home from work and usually get the sizes I need.

Previously I have worked at facilities that have always had machine shops and tool grind rooms where they resharpened drills and reamers so all I had to do was a 1 for 1 exchange for sharp cutting tools.

I think it may be time to start sharpening as many items as I can but have no experience in this area.

Anyone have any advice for sharpening bits?

Here are some sharpeners sold at Grainger.

http://www.grainger.com/Grainger/wwg/pr ... =Drill+Bit

http://www.grainger.com/Grainger/wwg/vi ... tPage=3248

Any one have any experience with this particular brand or any others on the market?

Thanx

prestwich · Post by **prestwich** » Sat Apr 15, 2006 9:02 pm

Never used one, so I can't offer any feedback on that. But, I'm surprised that you have to buy your own drills. Cutting tools are almost always considered "expendable shop supplies" and therefore the responsibility of the employer.

Back in the old days (so I'm told

) one of the first things a machinist learned was how to sharpen a drill on a grinding wheel, and it's not a bad skill to have.

I'd think the split-points would be a bit of a challenge to hand-sharpen, and maybe the drill doctors can't even do 'em. I'd definitely consider a #30 or smaller to be more or less disposable.

If you do buy a sharpener, let us know how it works out for you!

captain_john · Post by **captain_john** » Sat Apr 15, 2006 9:40 pm

Yup! I use a Drill Doctor. We have one at school and it is the BOMB!

I think they were bought out by DeWalt, but I am not sure.

For aluminum, I only use new bits. For steel, I always resharpen them.

It is an acquired skill. Not everyone knows how to use one. I think I make them sharper than the factory! Besides myself, there is only one other guy at school that knows how to use it. That is good because if it is screwed up, I know who to blame!

CJ

aparchment · Post by **aparchment** » Mon Apr 17, 2006 12:46 am

Hey John:

We will have to compare notes on the drill doctor. I am not so sure I like mine.

BTW, I need your address to return the squeezer yoke. Drop me a private message when you get a chance.

Antony

Dan A · Post by **Dan A** » Tue Apr 18, 2006 8:20 pm

I learned to sharpen bits on a grinder from my Father who was a pretty good machinist. The #40 bits are a little bit hard to sharpen properly, but the #30 and larger are not a problem. I would suggest having a good supply of #40's and a few #30's and two or three of the larger bits. You will use the #40's the most since the skins all use 426-3 rivits and that's the majority of the work. What ever path you choose to go having correctly sharpened bits will save you a lot of heart burn!
Enjoy!!

Dan

Snap · Post by **Snap** » Tue Apr 18, 2006 9:18 pm

I was just wondering, how often do the drill bits wear out?

I was looking on Avery's (I seem to be doing that alot lately) and you can get a pack of 6 for not much money. This makes me think that you will go through them quickly.

What have you Guys and Gals noticed?

captain_john · Post by **captain_john** » Wed Apr 19, 2006 5:44 am

I have gone through FAR LESS than I had previously envisioned!

A set of six will get you well onto the wings!

CJ

Wicked Stick · Post by **Wicked Stick** » Wed Apr 19, 2006 9:28 am

I'm starting to use the reamers more often now instead of the drill bits to open up the pre-punched match holes to final size. They produce a nice round hole with less burr's.

They are $9.00 a piece from Avery for the #30 & #40 sizes. More expensive but they work so much better and save in de-burring time.

I also use reamers to final size holes for bolts and to clean up holes on the powder coated weldments so the bolts fit perfectly with no slop by using slightly undersize reamers. (eg. .2490 for a 1/4 inch hole.)

prestwich · Post by **prestwich** » Wed Apr 19, 2006 1:02 pm

I'm with you on the reamers, Dave. They *are* the correct tools for the pre-punched kits. Even for those holes that aren't punched, I drill undersize and then ream. (e.g. 3/32 or 1/8 drill, then #40 or #30 ream.)

Reamers, like countersinks, are used at very slow RPMs.