Historical
ANSI/ASME B1.1-1989
Unified Inch Screw Threads (UN and UNR Thread Form)
This Standard specifies the thread form, series, class, allowance, tolerance, and designation for unified screw threads. (In order to emphasize that unified screw threads are based on inch modules, they may be denoted unified inch screw threads.) Several variations in thread form have been developed for unified threads; however, this Standard covers only UN and UNR thread forms.
CONTENT PROVIDER
American Society of Mechanical Engineers [asme]
American Society of Mechanical Engineers [asme]