alternative drill work

For many knives I have been using commercial available pivot screws.There good for most of the folding knives and it’s easy to find the matching step drill bits . Now I am making 2 prototype folders for a design contest and I decided to use custom pivot screw parts.A special knife needs some extra attention so I ordered large 1/2″ head  pivots . A big difference to the common 5/16″ head of the smaller pivots.These custom made pivots still have the same shaft dia 7/32″ but to drill the 1/2″ recesses into the G10 I need a uncommon step drill.Custom step drills are expensive and hard to find so I tried some alternative way to counterbore the material.Below a picture to compare the sizes.

Instead of using a common step drill I start with a wood drill bit of the size 1/2″.The sharp point enables boring at the exact location in the G10 and makes the right form to bore the center with a steel drill bit.The recess is not flat but the outer diameter is the exact size and thats most important .

Now I bore the center with a smaller drill bit .Here you can drill the right size to allow the pivot’s shaft but I used the matching size of another step drill.With a smaller step drill I flatten the bottom of the bored recess.Finally a larger drill bit is used to allow the pivot shaft.

Now I flatten the inside of the recess with a special file .Once clear the pivot head fits.Shortening the shaft or head of the pivot is done later when assembling the knife.

That’s it , with a few drill bits the job is done.Of course it only works in G10 , micarta , carbon fiber or wood .