本文件规定了用于钎焊金属的助焊剂的分类，并根据其性能和用途对这些助焊剂进行了描述，并给出了技术交付条件以及健康和安全预防措施。 本文件涵盖两类焊剂FH和FL。FH类焊剂用于重金属（钢、不锈钢、铜及其合金、镍及其合金、贵金属、钼和钨）的钎焊。FL级用于铝及其合金的钎焊。

This document specifies the classification of fluxes used for brazing metals and characterizes these fluxes on the basis of their properties and use, and gives technical delivery conditions and health and safety precautions. This document covers two classes of flux, FH and FL. Class FH is used for the brazing of heavy metals (steels, stainless steels, copper and its alloys, nickel and its alloys, precious metals, molybdenum and tungsten). Class FL is used for the brazing of aluminium and its alloys.