AWS A5.31M/A5.31-2022

Specification for Fluxes for Brazing and Braze Welding

This specification prescribes the requirements for classification of eighteen fluxes for brazing and braze welding. They are classified according to the filler metal, form, and activity temperature range. Classification is in accordance with a classification system that employs the designator FB to indicate fluxes for brazing and braze welding applications. In addition to selected tests for each classification, major topics include general requirements, testing procedures, and packaging requirements. A guide is appended to the specification as a source of information concerning the classification system employed and the intended use of the brazing fluxes. This specification makes use of both U.S. Customary Units and the International System of Units (SI). Since these are not equivalent, each system must be used independently of the other.