Drilling the countersink hole too fast can produce tear out or make it too deep.
How to countersink screws in light aluminum sheet.
Countersunk screw in through hole.
Countersinks have a countersink angle of 90 and for us standard 82 for countersinking screws e g.
You need a suitable countersink to countersink screws.
No c sink needed no metal removed from the sheet metal and more strength at the area of the screw head.
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.
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.
Use a cutter that matches the numbered size of your screw which is usually 6 8 or 10.
Drill the countersink hole at the marked spot.
Start the drill off at a faster speed to sink the bit cleanly then slow it down to make the countersink.
The countersink angle for rivets is 120.
Line up the tip of the drill bit with the mark you made earlier.