The best and smallest drill bits for a Pin vice

[Rattlecan Dan]

Anyone have a suggestion for the best and smallest drill bits for a pin vice?

[peteski]

You're not the first or last member asking this question. Searching the forum brings good answers:

 

 

[Shark]

Small drill bits break easily, so I usually get a pack from Harbor Freight for a couple bucks.

[Rattlecan Dan]

Thanks, Peter. And thanks for all the many handy tips and info on the forum. 

[bobss396]

I have a ship-load of carbide circuit board drills picked from the trash at work. These are poorly suited for hand drilling, although they seem to be popular. 

I did buy some small drills from HF. About a 3rd were ground incorrectly and not usable.

From the machine shop business I have a lot of small-ish drills since I bought them by the dozens. But few under 1/32".

I found a source on eBay with free shipping that sells Walther drills. I recently picked up some #71 to #76 HSS drills and they work well. I have a couple packets of #79 and #80 HSS drills that I rarely use.

[TonyK]

This is what I've used for years from Micro-Mark. Not cheap but they're good.

[Mike 1017]

I agree with Tony. The Micro-Mark are the best I buy the ones that come in a six pack

No. 76 Drill Bits (Pkg. of 6) – Micro-Mark

[peteski]

Yes, all those are good options which have been mentioned in the original 2 threads. 

[bobss396]

We have a tool vendor at local-ish shows who has a small drill assortment. BUT... the case they are in, you need 3 hands to open it up.

[Ace-Garageguy]

23 hours ago, bobss396 said:

...I did buy some small drills from HF. About a 3rd were ground incorrectly and not usable.

Yup.

That's a very real problem, and why I stopped trying to save a couple of bucks.

You may as well burn your money.

[bobss396]

13 minutes ago, Ace-Garageguy said:

Yup.

That's a very real problem, and why I stopped trying to save a couple of bucks.

You may as well burn your money.

For paying jobs, I'd buy drills in packs of 12, usually screw-machine type, some TiN coated. The costs were figured into the job.

I still have a crazy assortment of drills, end mills, saws and various cutters.

I have an account with one tool house, but the warehouse moved too far to be convenient.

eBay is my tool go-to lately. I shop the industrial section and can usually find made in the US drill packs.

[Skip]

Harbor Freight and even some of the eBay drill bits that I have purchased do not seem to cut plastic very well. Even when used in a pin vise or by hand. Many of these bits have micro-burrs on the cutting edge. My cure there is run the bit lightly across a good fine grit sharpening stone (water or oil stones, I like water stones from experience). It gets the very fine micro-burr that many of drill bits have on them, even from some high-end drill manufacturers. When cutting metal, as most of the drill bits are intended for, the micro-burr is taken off almost immediately by friction so it's not an issue.  I've also found burrs on McMaster Carr drill bits before, normally they will replace them no questions asked. While working in Aerospace machine shops, I learned about dressing the cutting edges of drill bits, something a lot of machinists do even on larger bits to make them cut the material better.  Just be careful that you get the same cutting angle on the drill bit that was ground on it in the first place, use the finest sharpening stone you have available to you and work slowly, testing on a piece of scrap as you go. Normally, all it takes is a couple short, quick strokes across the sharpening stone, that's it, so don't overdo it! Do the examination and re-cutting under magnification, like through your magnifying glasses or loupe lenses so you can see what's going on.  Look at it this way, if you cut the angle wrong and it doesn't work, what are you out? The drill wasn't working for you in the first place! Working in machine shops where tool and die work was performed, I got to inspect many specialty drill bits under an optical comparator under magnification the burrs and differences from one bit type to another is sometimes pretty significant.

The carbide Circuit Board drills are meant to be spun at a higher speed, although they will and do cut styrene/plastics quite well as many have found.  When I use a Circuit Board drill bit, normally it's out of an appropriate sized machinist's pin vise. I have a set of Starrett Machinist Pin Vises. There are cheaper Chinese versions on eBay as well, it's been my experience with them that the threads on the thimble are coarser than on the Starrett and tend to be slightly stickier most won't even notice it. That said, the Chinese Machinist's Pin Vises work OK with for me, and I'd recommend them with those reservations. Using the Pin Vise with the Circuit Board drill bits will also cut down on snapping these brittle bits off as easily, you'll still snap a few but held in a Pin Vise there is more control over the side forces of the bit that tend to snap them off.  Examining these bits, even the cheapest Chinese bits, I have never found a burr, that's one reason they cut quickly right out of the box every time until they break. You'll probably never wear one out on plastic!

That said, be extra careful with those Carbide Circuit Board bits, they are super brittle and are meant to be turned in a collette in a machine spindle where there is zero side play. When one of those bits do snap, it's easy to either cut across styrene or skin as they skitter across the surface scarring and cutting anything they come across! Ouch! Don't ask me how I know! I just know!!