From right to left:
1) Same as #4 in the prior post: Spax 3/4 #6 self threading wood screw. Pilot hole drilled through the AlumaCorr, larger hole drilled in the top surface, drill clutch set to #2. Note no surface deflection.
2) Same round head screw test as in previous post. Drill clutch set to #6
3) pop rivet (towards center of sample). Nice and tight and just slight surface deflection.
4) Spax 3/4 #6 self threading wood screw. Pilot hole drilled through the AlumaCorr, larger hole (slightly smaller than in 1)) drilled in the top surface and then champfered it's edge using a wood countersink bit (shown in left side of pictures below), drill clutch set to #2. Note no surface deflection.
The Spax screws seem to be a little above the surface because their screw head is somewhat pancaked and has ridges underneath to help chew up the wood to shape the champfered edge while it is being drilled. I think it is these ridges that are sitting atop the aluminum surface here. A regular, non-Spax wood screw wouldn't have these and should fit tighter and more flush.
