How To Countersink Screws In Light Aluminum Sheet

For the flat countersink the countersink angle is 180.

How to countersink screws in light aluminum sheet. The countersink angle for rivets is 120. Secure a fluted countersink cutter in your drill that s the same size as your screw. No c sink needed no metal removed from the sheet metal and more strength at the area of the screw head. Slide the screw into the countersunk hole and run your hand over the surface of the metal across the countersunk hole to feel whether the head of the screw protrudes above the surface of the metal.

A fluted countersink cutter has a wider base that comes to a point and contains multiple cutting edges so you can make larger holes for the screw s head. You need a suitable countersink to countersink screws. Use a cutter that matches the numbered size of your screw which is usually 6 8 or 10. Countersinks have a countersink angle of 90 and for us standard 82 for countersinking screws e g.

Drilling the countersink hole too fast can produce tear out or make it too deep. Line up the tip of the drill bit with the mark you made earlier. Start the drill off at a faster speed to sink the bit cleanly then slow it down to make the countersink.