Tapering holes in front Bolster

#1
How do you taper the hole in the front bolster of a slip joint folder for the pivot pin. I want to tapper for 3/32 and 1/8 pins. When peening the pin do you just tap around the edges of the pin. I hear hitting directly on the top will cause the pin to swell.
 

Craig

KNIFE MAKER
#2
I use a 10 degree carbide taper turned by hand. I taper enough to see a ring about .040 wide in the hole. From the side it would look like a "V" at the outside (show side) of the bolster. Use a light hammer and lightly peen the pin straight down to swell the pin and fill the taper. Alternate sides and it will take a lot of taps with the hammer to get the tapers filled.
 

Oze

Well-Known Member
#3
Hello Craig, do you make your own pins or buy them? What is better for the pivot, a pin or screw in your opinion? Thanks.
 
#4
Desperate people have been known to use a 1 1/4 inch wood drill to taper a hole until you can get the right item! That triangle point does work slowly.
 

Oze

Well-Known Member
#8
Just ordered one reaming tool on ebay $4 delivered. Crazy how cheap something can be delivered around the world now. A mate of mine here in Oz needed two $40 parts for his motor bike. Being a tight ass he looked on the internet to see how cheap he could get them. Purchased to relay switches or similar, delivered to Oz from China for $1. That included postage. How can this work. Can not post a letter for that. Parts worked fine too.
 

C Craft

Well-Known Member
#9
Oze, the idea with the reamer is too let it do the cutting don't force. What you are really looking for is similar to a countersink that runs the thickness of the material that will allow for the pin to expand and keep the dreaded ghost ring from appearing!
 
#11
May I jump in here and ask: How do you adjust the pressure on the blade from the bolsters so that the blade can still move nicely but does not wobble sideways?
 
#12
Canesplitter,

Use a shim between the blade and liner when you start peening. Use some .003 shim stock or an old feeler gage with a "V" notch cut in it to fit around the pin. That way the shim is on 3 side of the pin. peen it until the tapered hole is filled then remove the ship. Take up the slack with light taps of the hammer checking often. Photo of shim.
LB55.jpg

Pin after it is peened.
189.JPG

Hope this helps.
 
#13
Craig, thank you very much for your advice, highly appreciated!
I will do as advised! Hopefully I can post a picture of the finished knife soon!

Cheers
Canesplitter