On Sat, 23 Nov 2013 02:39:29 -0800 (PST), Frank Thompson
wrote:

On Friday, November 22, 2013 10:08:16 AM UTC-5, Robert Macy wrote:
Went to add a structure to the studs and need to use screws to assemble

[no real way to pound nails in and pounding would damage existing

structure, so nails are OUT] BUT! vaguely remember some threads here

regarding using readily available 'sheet rock' screws causing failures in

a structure under load.

square vs Torx... which is preferable?

I prefer square. Never had one slip at all. Very little pressure
needed.