USER GUIDE TAPS Thread Standards Cylindrical threads Taper pipe threads UNC Unified coarse thread series NPT Taper pipe threads UNF Unified fine thread series NPTF Taper pipe threads (dryseal) UNEF Unified extra-fine thread series NPTR Taper pipe threads for railway equipment UN Constant pitch series - threads PTF-SAE SHORT Taper pipe short with constant pitch of T.P.I. threads (dryseal)-SAE 4, 6, 8, 12, 16, 20, 28, 32 PTF-SPL SHORT Taper pipe special UNS Selected combinations - threads threads (dryseal)-SAE with special dia. - pitch combinations PTF-SPL EXTRA SHORT Extra short UNJ Unified threads with constant pitch special threads (dryseal)-SAE with radius on minor diameter from SPL-PTF Special taper pipe dryseal threads 0.15011 pitch to 0.18042 pitch NGT National American taper pipe threads UNJC Unified coarse thread with radius on SGT Special taper pipe threads minor diameter from 0.15011 API American Petroleum pitch to 0.18042 pitch Institute taper pipe threads UNJEF Unified extra-fine thread with radius on minor diameter from 0.15011 pitch to 0.18042 pitch Trapezoidal and saw tooth threads UNJF Unified fine threads with radius on ACME-C ACME Self-centering threads minor diameter from ACME-G ACME Generical application 0.15011 pitch to 0.18042 pitch STUB-ACME ACME Flat threads with reduced thread depth Pipe cylindrical threads 60º STUB-ACME ACME Flat threads with 60º flank angle NPS Cylindrical threads for pipe N BUTT American National Saw tooth threads NPSC American Standard for pipe coupling NPSF American Standard for internal threads on pipe, dryseal British Standard NPSH American Standard for cylindrical BSW Whitworth British Standard coarse pitch threads for pipes, joints and nipples BSF Whitworth British Standard fine pitch NPSI American Standard for internal WHIT Whitworth Standard special pitch cylindrical threads on pipe (dryseal) R British Standard external threading NPSL American Standard for cylindrical for taper pipe (dryseal) (already BSP-Tr) threads on pipes for nuts Rc British Standard internal threading NPSM American Standard for cylindrical taper thread for pipe (BSP-Tr) threads on pipes for mechanical joints Rp British Standard cylindrical NGO American National pipe threads for thread for pipe (already BSP.PI) gas exhaust BA British Standard Association threads NGS American National pipe threads for gas BSC British Standard threads for bicycles CEI British Standard for bicycles Taper pipe threads ANPT Taper pipe threads for Army, Navy and Airforce F-PTE Taper pipe fine threads (dryseal) 736 736 ISCAR ISCAR