ASTM F138-19 PDF

Full title and description

Standard Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for Surgical Implants (UNS S31673). ASTM F138-19 specifies chemical, mechanical and metallurgical requirements for wrought bar and wire forms of this implant-grade stainless steel, including permitted product forms, heat treatment/condition, surface finishes, and required testing.

Abstract

This specification covers wrought 18Cr-14Ni-2.5Mo stainless steel (commonly referenced as 316LVM / UNS S31673) supplied as bar, wire, and fine wire intended for the manufacture of surgical implants. The document defines allowable chemical composition, microstructural requirements (ferrite and deleterious phases), mechanical property requirements (ultimate tensile strength, yield, elongation, hardness), product conditions (hot-worked, annealed, cold-worked, extra hard), surface finishes, and required acceptance tests and metallography.

General information

• Status: Active standard (current edition F138-19).
• Publication date: December 1, 2019 (designated F138-19 / 2019 edition).
• Publisher: ASTM International.
• ICS / categories: Medical devices and implants — implants for surgery, prosthetics and orthotics (approx. ICS 11.040.40).
• Edition / version: ASTM F138-19 (2019).
• Number of pages: 6 pages (official PDF/printed edition length as published by ASTM).

Scope

F138-19 defines requirements for wrought 18Cr-14Ni-2.5Mo stainless steel bar and wire used to manufacture surgical implants. The standard covers acceptable chemical composition limits, metallurgical structure requirements (material shall be free of delta-ferrite, chi, and sigma phases when examined by metallography), permissible product conditions and finishes, and mechanical property tests (tensile, yield, elongation, hardness). Units in either SI or inch‑pound systems are provided and treated independently. The standard also notes it does not address all safety concerns associated with use and that users must consider regulatory and safety practices.

Key topics and requirements

• Material designation: UNS S31673 (18Cr–14Ni–2.5Mo) — commonly used as 316LVM/implant-grade stainless steel.
• Chemical composition limits and heat analysis requirements to ensure alloy chemistry is within specified bounds.
• Metallurgical requirement: absence of delta ferrite, chi, or sigma phases on metallographic examination.
• Permitted product conditions: hot-worked, annealed, cold-worked, extra hard; fine wire furnished cold-drawn as specified.
• Surface finishes: cold-drawn, pickled, ground, ground-and-polished (varies by product form and buyer specification).
• Mechanical property tests: ultimate tensile strength, yield strength, elongation, and Brinell hardness (testing and acceptance criteria defined).
• Units: SI and inch‑pound units are given but are not exact equivalents and must be used independently.

Typical use and users

Intended users include medical device manufacturers (orthopaedic, spinal, trauma and other implant makers), materials engineers, metallurgical and quality-control laboratories, purchasing/specification teams, regulatory and compliance personnel, and suppliers of implant-grade bar and wire. Typical uses are implant components, fixation devices, pins, wires, screws, and other surgical implant hardware where corrosion resistance, biocompatibility, and defined mechanical properties are required.

Related standards

Standards commonly referenced alongside F138 include ASTM F139 (sheet and strip of UNS S31673), ISO 5832-1 (stainless steel for surgical implants), and other ASTM implant material standards for cobalt‑chromium and titanium alloys (for example F1537, F136). These related documents address other product forms, alternative alloys, or complementary test/processing requirements for implant applications.

Keywords

ASTM F138-19; UNS S31673; 316LVM; surgical implants; stainless steel bar; stainless steel wire; chemical composition; metallography; tensile strength; Brinell hardness; implant-grade stainless; cold-drawn; pickled; ground; 18Cr-14Ni-2.5Mo.

FAQ

Q: What is this standard?

A: ASTM F138-19 is the 2019 edition of the ASTM specification for wrought 18Cr-14Ni-2.5Mo stainless steel bar and wire intended for surgical implant applications (UNS S31673).

Q: What does it cover?

A: It covers allowable chemistry, metallurgical condition (no deleterious phases), mechanical properties (tensile, yield, elongation, hardness), permitted product conditions and finishes, and required tests for bar and wire used in implants. Units are provided in both SI and inch‑pound systems (to be used independently).

Q: Who typically uses it?

A: Medical device manufacturers, materials and metallurgical labs, suppliers of implant-grade metal, QA/regulatory teams, and design engineers specifying implant materials. It is used where a standardized implant-grade stainless steel bar or wire specification is required.

Q: Is it current or superseded?

A: The F138-19 edition (published in 2019) is the current ASTM edition referenced here; earlier editions such as F138-13a are superseded by the 2019 revision. Users should confirm whether any later amendments or reissues have been published after 2019.

Q: Is it part of a series?

A: Yes. F138 is part of a set of ASTM medical/implant material specifications that cover various forms and alloys (for example F139 for sheet/strip of the same alloy, plus separate ASTM standards for cobalt‑chrome and titanium implant alloys). These documents together support material selection and procurement in medical device manufacturing.

Q: What are the key keywords?

A: UNS S31673, 316LVM, implant-grade stainless steel, bar and wire, chemical composition, metallography, tensile/yield/elongation, Brinell hardness, cold‑drawn, pickled, ground, surgical implants.