本标准的目的是就以下方面建立标准螺纹的统一惯例:（a）螺纹术语；（b） 用于在图纸上、规定尺寸标准的表格中、其他记录中以及用于表示数学关系的螺纹特征的字母符号。本标准包括:术语表、插图、显示符号应用的图解表和螺纹系列名称表。本标准中规定的许多术语和符号与1984版之前的术语和符号有很大不同，因为在预期定义相同的情况下采用了ISO术语和符号。

The purpose of this Standard is to establish a uniform practice for standard screw threads with regard to the following: (a) screw thread nomenclature; (b) letter symbols for designating features of a screw thread for use on drawings, in tables that set forth dimensional standards, in other records, and for expressing mathematical relationship. This Standard consists of: a glossary of terms, illustrations, an illustrated table showing the application of symbols, and a table of thread series designations. Many of the terms and symbols specified in this Standard vary considerably from those prior to the 1984 issue, because ISO terms and symbols have been adopted where the intended definition is the same.