ARP4784 PERFORMANCE AND EVALUATION CRITERIA, SURFACE DEFECTS, REQUIREMENTS FOR

This SAE Aerospace Recommended Practice (ARP) provides the requirements for surface defects, performance and evaluation criteria for various defects and discontinuities encountered in aerospace couplings, tube fittings and hose assembly components. The discontinuities fall into three basic categories: inherent discontinuities, which are present in the raw material stock; primary processing discontinuities, which are caused by processes which work the metal down by either hot or cold deformation into semifinished products; and secondary processing discontinuities, which are associated with finishing operations which occur after rolling. This document is intended to be used in conjunction with existing callouts on government and industry standards. Recommendations of allowable discontinuities are only guidelines, and any government/industry requirements will prevail over this document.