ASME B1.21M-1997 PDF

Scope: 1.1 Scope This Standard establishes the basic triangular profile for the MJ thread form; provides a system of designations; lists the standard series of diameter/pitch combinations for diameters from 1.6 to 200 mm; and specifies limiting dimensions and tolerances. It specifies the characteristics of the MJ metric series of threads having a minimum 0.15011P radius at the root of the external thread, and also having the minor diameter of the external and internal threads increased above the ASME B1.13M thread form to accommodate the external thread root radius.

ASME B1.21M-1997 Referenced Document

ANSI/ASME B1.22M Gages and Gaging Practice for “MJ” Series Metric Screw Threads
ANSI/ASME B1.7M Screw Threads, Nomenclature, Definitions, and Letter Symbols for
ASME B1.10M Unified Miniature Screw Threads*， 2024-04-18 Update
ASME B1.13M Metric Screw Threads: M Profile
ASME B1.15 Unified Inch Screw Threads (UNJ Thread Form)
ASME B1.30M Screw threads - Standard practice for calculating and rounding dimensions
ASME B1.3M Screw thread gaging systems for dimensional acceptability - Inch and metric screw threads (UN, UNR, UNJ, M, and MJ)
ISO 261 ISO general purpose metric screw threads - General plan*， 1998-12-01 Update
ISO 965-1 ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data — Amendment 1*， 2021-09-29 Update