The sq. shape from the recess permits a more secure in good shape and lowers the potential risk of damage to the screw head.
An exterior Torx screw features a projecting head in the shape of a Torx screwdriver bit https://tamzinytsl282603.mybloglicious.com/49313707/how-types-of-screw-heads-can-save-you-time-stress-and-money