You can grind aluminum and brass on a belt grinder, but I don't recommend grinding them on a hard wheel. It loads up the spaces between the grit and causes problems. On the less critical side, it causes the loss of grinding ability, on the more critical side, it causes imbalance and overheating which can lead to failure of the wheel and a very dangerous shrapnel hazard! So If you value your eyes and other body parts, don't grind nonferrous metals on a hard wheel.
When grinding pins, don't overheat them! If they get too hot to hold your finger on the back side, stop grinding and let them cool. Forced air usually cools them fairly quickly.
If you use pins, you can counter sink them using a counter sink, the steeper the angle the better, a tapered hand reamer or
the tip of a spade bit. The counter sink doesn't need to go very deep, just deep enough so after you finish the pin head, it if flared enough so you can't pull the grips off over the pin. So, drill a hole of the correct size for the pin, lightly countersink, insert pins and trim a thumb nail's thickness above the surface of the grip. Once trimmed place the back side of the pin on an anvil or suitable substitute and gently peen the pin head, then flip and repeat the process. Do this with scrap material until you get consistent results and your pin heads are round when you finish sanding them down.
With flat head rivets you will need a counter bore or use a spot face to drill out a well for the head or the rivet or the washer on the back side to fit into without any excess area around the rivet. Hope this helps.
Jim Arbuckle ABS JS
