If you're in Canada, every contractor knows and usually prefers the Robertson (square head) screw head. Known for its tapered square head the Robertson screw head offers a lower risk of stripping during installation. In other countries the Robertson screw head is growing in popularity but the Phillips screw head continues to dominate by preference.
With the introduction of the Quadrex screw head in recent years, the features of both Robertson and Phillips have been combined.
By popular demand, Hammond has added a Quadrex screw head to it's lineup of rack screws under the SCREW series. The screw features a factory-installed nylon washer, starter tip and is sold in packs of 25, 50, 100 and 500. For screw quantities 50 and up, Hammond ships in a convenient resealable jar.