These days surgical Instruments are made from a variety of materials including composites, plastics, titanium, and (the more traditional;) stainless steel. Typically two types of stainless steel series are most commonly used for instruments manufacturing.
- 300 series (Austenitic) stainless steel, and
- 400 series (Martensitic) stainless steel.
The Austenitic steel cannot be hardened through heat treatment. The 304 grade is the typical grade used for surgical instruments and is suited for items which require some malleability, that is, they can be pressed or formed into another shape without breaking the metal. Cannulas, retractors, probes, mallets, and spreaders are amongst some of the instruments that are traditionally manufactured through this series of steel.
The Martensitic steel are low carbon steel that can be hardened and tempered through heat treatment process. Due to the strength achieveable through hardening process, this series of steel is more suitable for instruments that require strength and tough cutting edges. Bone cutters, clamps, forceps, needle holders, and chisels are some of the instruments that are traditionally manufactured through the 410/420 grade of this series of steel.