K. Downing, J. W. Vance, Veridiam, Inc., El Cajon, CA; R. S. Brown, RSB Alloy Applications, LLC., Leesport, PA
As surgical procedures have become more complex and non-invasive, the requirements for instruments have become more demanding. Proper material selection is critical in instrument development. The material properties that must be considered include bio-compatibility, physical and mechanical properties as well as fabricability.
Historically, UNS S30400 stainless steel has been used to make tubular components for surgical instruments. However, it has some significant drawbacks including poor edge retention and poor wear resistance. Precipitation-hardened alloys, such as UNS S17400 have been used for many years with limited success. While better than UNS 30400 the cutting characteristics and edge retention of UNS S17400 is marginal in the new, more demanding applications. UNS S42010 (TrimRite®) and UNS S46500 (Custom 465®) are newer precipitation-hardened alloys with improved cutting characteristics, edge retention and fabricability.
In this study, tests were performed to determine and compare the cutting characteristics and edge retention of various alloys used for cutting and shaping instruments. Finally, the ability to fabricate these alloys into tubular components necessary to manufacture cutting and shaping instruments is discussed.
Summary: Five stainless steels were evaluated for sharpenability and edge retention in applications requiring cutting during surgical techniques. The edge retention was evaluated in soft tissue cutting applications such as vascular punches and scalpel blades.
