T-STAR and T-STAR Plus screws are a design of screw made by SPAX®. They offer an unusual screw head design for an ultra-tight fit, contributing to maximum torque with the drill and very little chance of a ‘cam out’ where the drill bit slips out, even at unusual angles.
The major difference between the T-STAR and conventional screws is the hexolubular or star design. Originally developed by Camcar Textron as Torx, this is a gear-shaped bit groove with six spokes. The result is a fit with the drill bit that is practically airtight. This means that the drill can apply a huge degree of torque to the screw. T-STAR Plus adds a indentation to the screw head, which provides an even more secure fit, allowing for comfortable drilling even at odd angles like overhead.
ERoofing sells an impressive array of T-STAR screws, made by SPAX.