4.1 This test method is designed solely for determining comparative laboratory indices of performance. The results may be used for ranking alloys in order of increasing resistance to pitting and crevice corrosion under the specific conditions of this method. It should be noted that the method is intentionally designed to reach conditions that are sufficiently severe to cause breakdown of at least one alloy (Type 316 L stainless steel) currently considered acceptable for surgical implant use, and that those alloys which suffer pitting or crevice corrosion during the more severe portions of the test do not necessarily suffer localized corrosion when placed within the human body as a surgical implant.

1.1 This test method covers the determination of resistance to either pitting or crevice corrosion of metals and alloys from which surgical implants will be produced. It is a modified version of an established test2 and is used as a screening test to rank surgical implant alloys in order of their resistance to localized corrosion.

1.2 This test method applies only to passive metals and alloys. Nonpassive alloys (other than noble alloys) are susceptible to general corrosion and are not normally suitable for implant use.

1.3 This test method is intended for use as a laboratory screening test for metals and alloys which undergo pitting or crevice corrosion, or both.

1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.