23. Symbols for Standard Threads Intro ISO Thread symbol Kinds of thread Related Standard SP M ISO Metric threads ISO 261 UNC ISO Unified threads, coarse series ISO 263 UNF ISO Unified threads, fine series ISO 263 UNEF ISO Unified threads, extra fine series ISO 263 SL UN ISO Unified threads, constant pitch series ISO 263 G Parallel pipe threads ISO 228/1 Rp Parallel internal pipe threads ISO 7/1 Rc Taper internal pipe threads ISO 7/1 PO R Taper external pipe threads ISO 7/1 S ISO Miniature screw threads ISO 1501 Tr ISO Metric trapezoidal screw threads ISO2902 UNJC Aerospace - UNJ threads (coarse) ISO 3161 ST UNJF Aerospace - UNJ threads (fine) ISO 3161 UNJEF Aerospace - UNJ threads (extra fine) ISO 3161 UNJ Aerospace - UNJ threads (constant pitch series) ISO 3161 MJ Aerospace - MJ threads ISO 5855 ROLL GL Glass container threads ISO 1115 V Tire valve threads ISO 4570/1-3 CARBIDE Japan LONG Thread symbol Kinds of thread Related Standard M Metric screw threads JIS B 0205-1 - 0205-4 S Miniature screw threads JIS B 0201 UNC Unified threads, Coarse series JIS B 0206 HAND UNF Unified threads, Fine series JIS B 0208 TAPS Tr Metric Trapezoidal screw threads JIS B 0216 R Taper external pipe threads JIS B 0203 (JIS main book) Rc Taper internal pipe threads JIS B 0203 (JIS main book) EG (STI) Rp Parallel internal pipe threads JIS B 0203 (JIS main book) G Parallel pipe threads JIS B 0202 (JIS main book) PF Parallel pipe threads JIS B 0202 (JIS Appendix) PT Taper pipe threads JIS B 0203 (JIS Appendix) SPECIAL PS Parallel internal pipe threads JIS B 0203 (JIS Appendix) THREADS,GAUGES CTC Screw threads for rigid metal thin-walled conduit and fitting JIS C 8305 CTG Screw threads for rigid metal thick-walled conduit and fitting JIS C 8305 BC Cycle threads JIS B 0225 THREAD SM Screw threads for sewing machine JIS B 0226 (2001.2.20 repeal) MILLS E Electric socket and lamp-base threads JIS C 7709 V Tire valve threads of automobile JIS D 4207 CTV Tire valve threads of cycle JIS D 9422 DIES CENTER DRILLS Technical info 713