high precision tough materials critical factors costeffective solution cast iron highprecision drilling heat generated heat resistance upfront cost largescale operations smaller jobs generalpurpose drilling largediameter holes performance features manufacturing process efficient drilling highvolume operations highspeed drilling drill bit carbide inserts alloys equipped hss drill highspeed cutting highvolume production hss drills costeffective hss drill bit hss drills tend replaceable inserts make traditional drills making small projects speed hss drill bits similar conditions precision wood hss tools highvolume production choose significantly higher speeds highspeed steel widely alloys hardened steel specialized cutting tool large production volumes highly accurate perfect tool life making mild steel aluminium created equal choosing