Titanium
Titanium is the workhorse of permanent orthopedic implants — hip stems, knee components, spine cages, dental abutments. Grade 5 (Ti-6Al-4V) and Grade 23 (Ti-6Al-4V ELI) provide the strength-to-weight ratio and biocompatibility required for load-bearing implants, while commercially pure Grade 2 is used for surgical instruments and non-load-bearing applications. Titanium machines slowly and generates heat — proper coolant flow and tool selection are critical.