This article was kindly provided by
Elven Davidson, an amateur woodworker/handyman and a great believer in square –drive screws.
As an affidavit to the strength of the screws and their drive system I offer the following.
I was recently fastening a 2” x 2” R.H.S. to a 4” x 4” red gum fence post using a #14 x 3” Robertson’s thru’ one wall of the box section. I wanted a good tight fit so I had drilled the pilot hole small.
A bit TOO small as it turned out. Before it was “home” it sheared the gearbox on my 18v Lithium Cordless Driver set at its highest torque. Not the screw, or the Robertson driver, but the drill itself.
I finished the job by attaching a ¼” hex spanner to the Robertson driver.
That screw will NOT come loose.