This revolutionary document represents the most significant change to aviation welding standards in more than 30 years, including coverage in three areas never addressed in MILSTDs design, repair, and nonflight hardware. And, for the first time, there are authoritative procedures for weld repair of inservice existing aerospace flight hardware. In fact, the standards use of weld repair technology enables weld overhaul beyond the areas originally designated for a weld. Bolstering the excellent coverage on inspection is information to avoid both under and overinspection, arising from the D17 Committees position that, Choosing acceptance criteria beyond the capability of the welding process may lead to numerous inspection rejections, increasing costs. To help, tables on acceptance criteria one in U.S. Customary units, the other in SI units provide distinctions for Class A, B, and C welds. Also includes an annex offering Guidelines for Design, Analysis, and Fabrication of Weld Joints. D17.12001 emphasizes fusion welding of aluminumbased, nickelbased, ironbased, cobaltbased, magnesiumbased, and titaniumbased alloys using electric arc and high energy beam processes. SI metric equivalents provided. ANSI Approved.