Choosing the right material is critical for performance and tool life. For general-purpose metalworking, HSS (High-Speed Steel) is the standard. If you are drilling into stainless steel or hard alloys, you must specify M35 or M42 Cobalt (HSS-Co) bits, which offer superior heat resistance. For high-volume production lines requiring maximum precision and speed, Tungsten Carbide bits are the best choice, though they are more brittle and require a stable machine setup. For masonry and concrete, ensure the bits have a C2 or C3 grade Carbide tip.