August, 1998 - A new specialty alloy candidate for fracture fixation devices and implanted orthopedic devices for hips, knees and other joints has been developed by Carpenter Technology Corp., Reading, PA, for consideration by medical and surgical users in Europe.

The premium electroslag re-melted BioDur® 734 alloy is Carpenter's alternative to the well known Orton 90 and Rex 734 alloys, and a European version of Carpenter BioDur 22Cr-13Ni-5Mn alloy.

BioDur 734 alloy is a nitrogen-strengthened, austenitic stainless steel that compares favorably with BioDur 316LS stainless steel. The new grade has better corrosion resistance and higher annealed yield strength.It also is capable of a higher cold work strength.

Nominal chemical composition of the new alloy, which meets ISO specification #5832-9, is: chromium 20.5%, nickel 9.5%, manganese 4.0%, molybdenum 2.0% and balance iron.

The alloy is available from Carpenter in annealed, cold drawn wire and bar. Standard sizes range from fine wire to 33 mm round. Other sizes are available on request.