ISO 15374:1998

Overview

ISO 15374:1998, "Implants for surgery - Requirements for production of forgings," specifies production requirements for forgings used as semifinished products in surgical implant manufacture. It covers forgings made from stainless steel, unalloyed titanium, titanium alloys and cobalt‑based alloys, and sets expectations for material composition, process control, mechanical testing, microstructure, traceability, identification and delivery.

Key topics and technical requirements

• Material compliance: Forging stock must conform to the relevant parts of ISO 5832 (metallic materials for implants).
• Process control:
  • Heating temperature before forging shall be controlled. For titanium and titanium alloys, heating must minimize hydrogen pick‑up.
  • Presence of shear bands is acceptable only if they do not impair application.
  • Hot‑forged surfaces must be descaled and pickled if necessary; titanium forgings require removal of oxide scale and any oxygen‑enriched case.
  • Post‑forging heat treatment conditions are to be agreed between supplier and customer.
• Hydrogen limit (titanium): For unalloyed titanium and titanium alloy forgings, hydrogen content measured on the smallest cross‑section shall not exceed 0.015% (mass fraction).
• Mechanical testing:
  • Tensile test specimens to be prepared and tested in accordance with ISO 6892.
  • Annealed forgings must meet tensile property requirements of the corresponding part of ISO 5832.
• Microstructure and grain size:
  • Forgings must be free from signs of underheating/overheating and harmful segregation; surface defects detrimental to the finished implant are not acceptable.
  • Unalloyed titanium grain size shall be uniform and not larger than ASTM E112 grain size 5.
  • Titanium alloy microstructure acceptance referenced to ETTC Publication 2 and corresponding ISO 5832 parts.
• Traceability and documentation:
  • Maintain batch (lot) traceability through manufacture and delivery.
  • Batches must be packaged and labeled with manufacturer ID, quantity, design reference and batch number.
  • Deliveries require a release certificate (or EN 10204 declaration) including supplier, purchase number, applicable standards, heat number, batch number, test report and delivery date.

Applications and users

ISO 15374 is intended for organizations involved in the production and supply of semifinished forgings for surgical implants, including:

• Implant manufacturers and OEMs specifying forgings for orthopedic, dental or other surgical devices
• Forging mills and subcontractors producing implant-grade stainless steel, titanium and cobalt alloy forgings
• Quality, regulatory and procurement professionals ensuring traceability, test reporting and compliance for implant materials
• Metallurgists and process engineers controlling heating, surface treatment and microstructure for implant applications

Related standards

• ISO 5832 series (parts 1–12) - metallic materials for implants
• ISO 6892 - tensile testing of metallic materials
• EN 10204 - types of inspection documents / release certificates
• ETTC Publication 2 - microstructural standards for alpha+beta titanium alloy bars

Keywords: ISO 15374, forgings for implants, titanium forgings, stainless steel forgings, implant traceability, microstructure, hydrogen content, mechanical testing.