"Jeff Wisnia" wrote in message
et...
Soup Nazi wrote:
which screw head is better? for a non-slip power driver's use. And what
type for shear-resistance? outdoor/indoor etc?



I believe the Roberts (square drive recess) is better in many ways. It
stays on the driver "no hands" pretty well without needing magnetism.

The recesses "strip out" less frequently than Phillips do, which means the
bits will last longer, 'cause they wear when they spin in the screw head
recess.

Phillips was actually designed to slip out when power driven.