I bought the smallest ones X-acto had, the #55 through #80, but they don't say how the sizes work on them, is the higher the number the bigger they get, or the smaller they get. I bought the small set, then I bought the medium set, but they no longer have the medium set in stock to where I bought them, to check it out.

Anyway I got them bolt-heads from Grandt Line, and they recommend to drill a hole to mount their bolt-heads so they stay better, but the smallest bit I have is still almost big enough for the whole head of the bolt to fall through it.

It didn't fall through it, but it was pretty sloppy, and I would like to have a little bit smaller hole. So if somebody could send me in the right direction, I'll thank you a head of time.

Kerry

A #80 is pretty dang small -- .0135 inch. What size Grandt line bolts are you using? And what are you using to drill? If you chuck them in a motortool, they may be melting a hole rather than actually drilling -- making the melted hole too large.

I normally use about a #72 (.025 inch) for Grandt Line bolts.

You can buy replacement drills at most decent hardware stores.

Hope this helps ...

Micro-Mark maybe? Here is the link.

http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Department&ID=110

The bigger the number... the smaller the drill Kerry.
# 80 is the smallest you can get at a realistic price.
They do make them smaller, but # 80 is pretty darn small.
Smaller than #80 will run you between 10 to 20 bucks PER drill. I got a link somewhere, where you can order them, but personally, I have never needed a drill smaller than a #80. (if you want the link...PM me and give a few days to find it, since my booksmarks are in NO kind of order..... LOL)
As for drilling for Grant lines, I use just about the same sizes that Hollowpoint uses, in that general area, since the little pins on the grant lines aren't perfectly round... a #72 maybe too small, or too large, go up or down a size from there. As Hollow point pointed out, these drills are for use in a pin vise, or pin drill, not a motor tool.
Replacements are usually sold in a decent hardware store under the Brand name DIXON, and run about a buck each, at least in my area. You might want to google and check for their website.
You can order tubes of 10, of each each size from Model-expo also. I stocked up when they were having their clearence sale, and paid a buck a tube for ten. I don't know what they are charging for them now.

Ciao straightedge,
Steve is absolutely right. Micromark is the way to go. They sell the smallest ones anywhere. They sell them in sets or individually.
Ciao for now
Rob