View Full Version : 1/8" pins won't fit 1/8" hole

10-26-2010, 11:53 AM
I'm working on my first knife, a kit from Jantz.

The knife blank is pre-drilled with 1/8" holes. Rather than using the pins that came with the kit, I want to use 1/8" mosaic pins (that I also purchased from jantz). The probem is they won't fit. I don't have a micrometer to check the pin thickness (diameter).

Idiot question here:
Should I use a reemer to bore out the holes in the handle?
or, another drill bit?

If so, what size should I use (of either one)?


Mike Turner
10-26-2010, 12:17 PM
Use a #30 drill bit

10-26-2010, 12:17 PM
A 1/8" pin will not fit into a 1/8" hole.....they are both the exact same size (.125").....what you have to do is the following:

For a 1/6" pin, use a #52 drill bit
For a 3/32" pin, use a #41 drill bit
For a 1/8" pin, use a #30 drill bit

What you have to remember is that there is a difference between bolt/screw sizes, and pin material sizes.... bolts and screws are manufactured slightly under size, so they will fit INTO specific sized holes (example: a 1/4" bolt/screw shank is .245", and a 1/4" drill bit is .250", so that the bolt will fit through the hole.) Pin stock is manufactured to the exact size it's labeled as....... 1/4" pin stock will be .250" in diameter, which means it will not fit through a 1/4" hole, which is also .250".
The hole must always be a few thousandths larger than the pin diameter in order for the pin to go through the hole.

Dan Pierson
10-26-2010, 12:19 PM
You always need to either reduce the pins a bit or use a slightly larger bit. I have a set of numbered bits
and go up a few thousands from the nominal hole size.

Yes, for really precise fit: drill slightly under size and use a reamer but, IMHO, this isn't necessary for handle

10-26-2010, 12:37 PM
Thanks guys!

10-27-2010, 12:55 PM
My suggestion was going to be to reduce the pin size very very slightly, but Dan beat me to it... If you get it too small, move to the next section of pinstock. Its hard to put material back if you overdrill.

Josh Dabney
10-27-2010, 01:46 PM
Thought it worth mentioning that your kit blade is most likely stainless and has a tang that is hardened. With a reamer you'ld probably be ok but trying to open up the hole with a drill bit will most likely just ruin the bit.

My first couple knives were kit knives and I did the same thing you're wanting to do. I picked up a set of diamond needle files from Harbor Freight for $7.99 and used the round one to open the hole up a little to get the pinstock through.

Thank you Ed for sharing your advise of using the numbered bits ! I took your advise a long time ago and haven't had a problem since. Little tips like that help ALOT when your a newbie :)


Fred Rowe
10-27-2010, 02:33 PM
If you purchased the kit from Jantz supply and the pin is oversize, I would ask for new material; a new 1/8the inch section of mosaic pin.

You will find oversize stock in every dimension and in all materials these days. A caliper or micrometer is one tool you will find much use for in the knife shop.

If you want your pins to fit perfectly; use an undersized drill bit to drill the hole, followed by the corresponding ream. The reason for this is a drill bit does not drill a round hole, it is more elongated than round. An 1/8th inch ream cuts a perfectly round hole when it is run through the undersized starter hole. If you have true 1/8th inch round stock they will fit the hole perfectly.


10-27-2010, 02:53 PM
Yes, it's hardened stainless 440. I was actually thinking of taking a butane lighter, and heating the pin holes (try it on 1). If that didn't work then either a file, or small dremel stone.

10-27-2010, 03:05 PM
Wouldn't it be just as effect to put the pin material in your drill and spin it lightly in some steel wool or fine sandpaper?

Dan Pierson
10-27-2010, 04:41 PM
Yes, that can be done. Be careful not to squish the pin out of shape -- especially if it's a mosaic pin. Don't ask how I know...

Jim Adams Customs
11-02-2010, 06:40 PM
Dan has it right. Just sand down the pins. Pins holes are not critical on a fix blade. Because your epoxy will fill any extra space.

A Knife blank should be harden. So unless you spend 20.00 plus on lapping tools and Barrel Lap the hole, because your only talking about less than a .0001 of an inch. You can't drill or ream an .0001, Plus a .251 Carbide reamer is $40.00 Plus

Cliff Fendley
11-03-2010, 10:03 AM
Use a drill or your hand to spin the pins on a 220 grit slack belt until they fit. Gives a good fit with something for the epoxy to grab. Done in a matter of seconds.