And I would avoid the countersinking because it takes away "THREAD bearance", and cuts the bearance for a #90 screw from approx 3 1/2 turns burried in the 'meat' of the brass to less than 2 turns. Even a shallow angled flat head mach screw will do this. Even eyeglasses have better bearance than this in the nose standoffs.I prefer to avoid the nuts and the countersinking operation. Vern