Drill Bits

What are you guys using for drill bits for pinning, bottle bosses, whatever? I've been using Enco import bits for pinning, jobber length, don't remember what angle, black oxide; not too impressed, they seem to dull very quickly, break easily. I'm about to freshen my supply and am leaning towards 135 degree split points, screw machine length, black oxide, Enco again, possibly Hertel brand (import, or domestic)

Even the larger sizes for bosses (std bits from Lowes or Home Depot) walk enough to annoy (yes, even after spotting) so I figure I'll use the same type as above....or just use spotting drills.

Or would straight flute, stub length be the ticket, or perhaps something else?

Interested in feedback, recommendations, reactions.

Thanks

Try center drills.

Center drills are awesome. For other drills never go cheap. Cobalt drills aren't that much more and last a lot longer. Screw-length is often nice.

Enco or McMaster Carr have plenty for decent prices.

Good technique will also greatly lengthen drill life.

+1 on the center drills, especially for bottle bosses.
Learning to sharpen bits was an awesome decision as well.

Another +1 for the center drills for starting, and for thin wall tubes and shallow holes I always finish with "stub drills" (short length bits, less drill wander).

2¢

Fantastic! Thanks for the photo Curt. That's the answer - I shall make the switch to center drills.

Sharpening my conventional twist bits....I've tried to do that freehand and not been too successful but it seriously grates me to toss a bit for the loss of an edge. How is it done?

john grinding a drill is not easy on small bits if your learning

get yourself a big old drill like 1" in diameter then get yourself a book describing drill nomenclature

try to sharpen the big drill ,but basically as an apprentice we were taught both chisel edges should be equal otherwise your drill is going off centre and going to cut big

Attachment 69330

Attachment 69331

once you get the big drill down as its easier to see whats happening ,move onto smaller drills

Note to self (and others): Shop Made Drill Sharpening Jigs
Interesting.

Ohhhhh…Me Likey! :bigsmile:

I sharpened all my cheap drill bits with a Drill Doctor. They work better than they did when they were new. https://www.drilldoctor.com/

thanks for this great chart. I only sharpen bits by hand if i am using them to enlarge a hole. if i need centering accuracy i use the drill doctor. and yes those center drill rock. spotting bits are pretty ace as well. that reminds me......Order more spotting drills.

Mike

sharpening by hand sucks for accuracy and leads to wondering bits, for general sharpening it works great. By machinist standards a drill doctor sucks, but is ok for most sharpening. If you really want to go to town I got a cincinatti #2 with sumitomo drill fixture I will sell you cheap to get it out of the shop, haha joking of course-but really I do and will.

Any way a split point can help alot, but for framebuilding type uses I think the centerpoints are best, just set them aside from your general drilling so you dont dull them.

Drilling is the best option to get perfection and work special, for my home and other little work I'm personally using drill that is a Bosch PS31-2A, and it's working powerful.

Drilling kit contains two bits!

+2 or is it 3 or 4 on the center bits. They are much stiffer have less run out and work like a champ. I bought mine as a set for a relatively reasonable cost from little machine shop. They have a basic set of number 1-5 for $9 and a cobalt set for $20

https://littlemachineshop.com/produc...4859&category=

Edgar