The material of the hand tap directly determines its lifespan and performance. For general purposes, High-Speed Steel (HSS) is the industry standard due to its balance of toughness and wear resistance. For harder materials like stainless steel, look for HSS-Co (Cobalt-infused) taps, which offer superior heat resistance. For high-volume production, Tungsten Carbide taps are preferred for their extreme hardness, though they are more brittle. Always ensure the supplier provides a material analysis report to verify the grade.