scope:

GENERAL

The purpose of this standard is to establish uniform practices with regard to: (1) screw thread nomenclature, and (2) latter symbols for designating dimensions of screw threads for use on drawings, in tables of dimensions which set forth dimensional standards, and in other records, and for expressing mathematical relationship.

The standard consists of a glossary of terms, two tables of screw-thread dimensional symbol, four illustrations showing the application of dimensional symbols, two tables of thread series and dimensional designations, and an index. Supplementary information is provided in two appendixes.

Typography. In accordance with the usual practice in published text, latter symbols and latter subscripts, whether upper or lower case. Should be printed in italic type. An exception is Greek letters; Greek capital letters are always vertical, and lower case always resembles italics, In manuscripts this is indicated by underlining each symbol to be italicized . coefficients, numeral subscripts, and exponents should be printed in vertical Arabic numerals. Standard mathematical notation should be followed.