Torx Pan Head Triangular Thread Forming Screws for Soft Metal
Steel zinc plated screws with case hardened.
The triangular shank presses tightly as it forms threads, so screws resist loosening in soft metals such as brass, aluminum, and copper. Torx drive that allows you to apply extra force with less slippage or damage to the recess. Made from steel, they're zinc-plated steel to resist corrosion in wet environments.