This document specifies the basic and design profiles for ISO inch screw threads (UN and UNR).
UN applies to both internal and external threads. UNR only applies to external threads. A flat or rounded root contour, due to the threading process, is specified for UN threads, while only a defined rounded root contour is specified for UNR external threads.
This document is applicable to the inch fastening screw threads.
PUBLISHED
ISO 68-2:2023
60.60
Standard published
Oct 5, 2023