ASME B1.1-2003
Unified Inch Screw Threads, UN and UNR Thread Form

Standard No.

ASME B1.1-2003

Release Date

2003

Published By

American Society of Mechanical Engineers (ASME)

Status

Be replaced 2020-06

Replace By

ASME B1.1-2019

Latest

ASME B1.1-2019

Replace

ASME B1.1:1989

Scope

This Standard specifies the thread form, series, class,allowance, tolerance, and designation for unified screwthreads. (In order to emphasize that unified screwthreads are based on inch modules, they may be denotedunified inch screw threads.) Several variations in threadform have been developed for unified threads; however,this Standard covers only UN and UNR thread forms.For easy reference, a metric translation of this Standardhas been incorporated as Nonmandatory AppendixC. Nonmandatory Appendices A through E containuseful information that is supplementary to the sectionsof this Standard.

ASME B1.1-2003 Referenced Document

• ASME B1.2 Gages and gaging for unified inch screw threads
• ASME B1.3 
• ASME B1.30 Screw Threads: Standard Practice for Calculating and Rounding Dimensions*， 2024-04-18 Update
• ASME B1.7 Screw Threads: Nomenclature, Definitions, and Letter Symbols Revision of ANSI B1.7M-1984*， 2006-01-01 Update
• ASME B47.1 Gage Blanks with Errata*， 2024-04-18 Update
• ASME Y14.5 Certification of Geometric Dimensioning and Tolerancing Professionals
• ISO 68 ISO general purpose screw threads; Basic profile

ASME B1.1-2003 history

• 2020 ASME B1.1-2019 Unified Inch Screw Threads (UN, UNR, and UNJ Thread Forms)
• 2003 ASME B1.1-2003 Unified Inch Screw Threads, UN and UNR Thread Form
• 1989 ASME B1.1-1989 Unified inch screw threads (UN and UNR thread form)
• 1935 ASME B1.1-1935 Unified Inch Screw Threads, UN and UNR Thread Form

ASME B1.1-2003 -All Parts