I found a sale on 3.5mm solid carbide twist drills on EBay. Of course 3.5mm is 0.1378 inch which falls right in between wire #28 and #29 which are the common drill sizes for 8x40 screws. I ordered 50 of them just because of the price which worked out to $105.89 USD for the lot including shipping charges which were included to Canada. So, they worked out to $2.12 a piece USD. Not that I was trying to hog them, but I wanted to see just what the hell they were and if they were worth it before I told anyone else. I have been burned before on crap like this. They came in the mail a couple of days ago and they are clearly seconds as the grind in the flutes looks like it was done by a cross eyed, hermaphroditic, constipated beaver. But I poked a hole in a file at about 1000 rpm which is far to slow for a drill that size and it showed no ill affects what-so-ever and went through the file like smoke through a gun with no heating and was bang on for size. They may not evacuate soft materials at 10,000 rpm in a CNC, but for mental cripples like ourselves poking holes in hardened receivers, they will work fine. Brownells wants about $17.00 gunsmith cost plus shipping for #28 carbide so it is quite a savings. You might as well say that you are getting 50, for the price of 7 and they are 2 flute, not three like the ones Brownells sells so they are easy to resharpen.


http://www.ebay.ca/itm/322430581015

28 29 drill by Rod Henrickson, on Flickr

Just to add: 3mm is the same as wire #31 and I buy them dirt cheap in carbide off of Ebay too.

My pet beaver is offended, but the information is good to have.

quote:

Originally posted by dpcd:
My pet beaver is offended, but the information is good to have.

Almost all Americans are offended these days. Except the Ole Peckerheads. They've all turned into a bunch of panty waste, snowflakes! I think it has something to do with the potty training.

LMAO ROFF

And I guess you can read the Chinese directions !

OT.I remember going to a large affair in Toronto at a chopsticks only Chinese restaurant.
The other white guys couldn't understand how I could use chopsticks so well !

quote:

Originally posted by mete:
And I guess you can read the Chinese directions !

OT.I remember going to a large affair in Toronto at a chopsticks only Chinese restaurant.
The other white guys couldn't understand how I could use chopsticks so well !

Can't read a lick of it. But I speak enough mandarin to get slapped ordering food at DimSum. Most people I grew up with can use chopsticks as will as a fork. Where I was raised was one of the areas where the Japanese were imprisoned during WWll. They got to know the locals and fit in so well that a lot of them stayed after the war and started businesses and raised families. When I was going to school (about 6 years old) one of the grownups made a side comment to someone else that one of my best friends was Japanese. I didn't have a clue what the hell they were talking about and asked my mother what it meant after school and she explained it to me. Hell, all that time, I though Harry just had bad vision and squinted a lot.

Forgive my layman's ignorance speerchucker, but what is #31 used for?

I use that size for 6-48 taps. I think it can also be used for 1/8" aluminum rivets(or maybe that is a #30, I forget)

Thank you Roger.

RogerR is correct. In this case it's the old Tomayto or Tomahto madness. Gunplumbers have always needed good #31 or #32 drills because 6x48 is one of the most common gun screws required. It holds 90% of our sighting apparatuses on. In the case of the old Mausers, Springfields, Enfields, Savage 99s and a host of others the material is almost too hard even for good cobalt drills. For years I have looked for a cheep source for carbide drills, other than Brownells which is basically a high end fashion boutique for gunnuts. It was always the same story. #31/#32 HSS is tough to get. #31/#32 cobalt is really tough and carbide is almost impossible. Until you ask for 3mm carbide that is. The size 3mm is so common that you can't toss a stone without hitting a 3mm drill. Basically #32 is .1160 inch. #31 is .120 and 3mm falls right in the middle at .1181 inch.

Thanks for the tips. What type of Tap is best to use for 8-40, and 6-48 after drilling through a piece of Remington Hide or Mauser Hide?

The best that I have used are those Reiff & Nestor taps that Brownells carries. I looked into ordering them direct once a few months back, but there was really no savings over Brownells.

Score another win for the boutique. Thanks, I'll get a couple.