"Gramp's shop" wrote in news:effd5331-4ba2-44a6-9a68-
:

The woodworkers show was in town today and I brought one of the broken screws and a
sample to get some opinions from the graybeards. Here's what they had to say:

1. Square drive screws don't allow the driver to slip off -- like philips head -- when the screw
is tight leading to breakage if I overtighten.
2. Screw should be lubed -- soap or wax.

Wax only, never soap. Soap will absorb water from ambient humidity, which promotes
corrosion of the screw.