Surgical grade (medical grade) tantalum – i.e. tantalum used in medical devices, is specified in a number of standards like:
- ASTM F560: Standard Specification for Unalloyed Tantalum for Surgical Implant Applications (UNS R05200, UNS R05400)
- ISO 13782: Implants for surgery — Metallic materials — Unalloyed tantalum for surgical implant applications.
- BS 7252-13: Implants for surgery — Metallic materials — Unalloyed tantalum for surgical implant applications
Where the British surgery standard BS 7252-13 is identical to the ISO 13782 standard.
The standards specify the chemical, mechanical, and metallurgical requirements for unalloyed tantalum used in orthopedic surgery or in the manufacture of implants. The material specifications in the standards are substantially similar.
Surgical Grade Tantalum Base Forms
A number of base forms are covered by the ASTM F560 standard.
ASTM F560 differentiates orthopedic grade tantalum products in the following way:
Tantalum plate is defined a flat product more than 0.1875 in. (4.7 mm) in thickness.
Tantalum sheet is flat products less than 0.1875 in. (4.7 mm) in thickness and more than 6 in. (152.4 mm) wide.
Tantalum strip is a flat product less than 0.1875 in. (4.7 mm) in thickness less than 6 (152.4 mm) in. wide.
Tantalum rod for surgery is defined as a material with a diameter between 0.125 to 2.5 in. (3.18 to 63.50 mm) supplied in straight lengths (round, hexagonal, or octagonal cross section). Commonly however the expression “rod” is used for straightened tantalum wire also below 0.125 in. / 3.18 mm. X-medics offer tantalum rod products as small as 0.500 mm.
Implantable Tantalum wire is defined as material up to 0.125″ (3.15 mm) in diameter.
Basic Surgical Tantalum Material Grades (R05200 vs R05400)
The ASTM F560 , ISO 13782 and BS 7252-13 specify two acceptable base grades:
Type R05200: unalloyed tantalum vacuum-arc melted or electron-beam melted ingots.
Type R05400: powder-metallurgy consolidated unalloyed tantalum.
There is no difference in the mechanical requirements of tantalum type R05200 and R05400. Concerning the chemical composition of the tantalum, slightly higher oxygen and hydrogen levels are accepted in R05400 surgical grade tantalum as compared to R05200 as can be seen below.