Thread: Making domed locking washers for re-pinning

A couple more thoughts. Aside from the aesthetics or pocket lint practicality of the domed pin...

Doming the washer leaves a little space between the maximum point of tension from the peened pin and the scale. The temptation is to give the pin just one more whack. This will be a bad thing if the pin is a little too short, so the washer gives you some standoff distance reducing the chance of this kind of mistake. A longer pin in the beginning gives you some room later for adjustment of tension if the blade loosens.

The spreading (aka upsetting) of the pin occurs in the opening of the washer now stood away from the scale and not the inside scale, reducing the chances of splitting. Plus it exerts the peened holding force over a wider area that is the diameter of the washer, rather than a smaller diameter that increases the risk of splitting. Greater holding power.

If you started with a soft brass block, it will work harden when you make washers. In the end, you have a harder block so steel or other harder material would be cool to start with if you're lucky, but brass will work and get better with age or more washers.