Thread Size Chart. Starting from the right--> 3/8ips thru 5/16-27 is hollow, the rest are solid. The number following the - (dash) is how many threads per inch. So 1/4-27 would have 27 threads per inch. We generally leave off the pitch on 1/8 thread, it is 1/8-27. The (finial) threads on the top of a harp are 1/4-27.
Dimensions of thread types, M - Iso thread (Metric) View the table, M Coarse Thread ISO 724 (DIN 13-1) M Fine Thread ISO 724 (DIN 13-2 to 11) NPT - Pipe thread, View the table, NPT ANSI B1.20.1, NPTF ANSI B1.20.3, G/R/RP - Whitworth thread (BSPP/BSPT) View the table, G = BSPP ISO 228 (DIN 259) R/Rp/Rc = BSPT ISO 7 (DIN 2999 replaced by EN10226)
BRITISH STANDARD PIPE THREADS (BSPP, BSPF) - Malone
British Standard Pipe(BSPP, BSPF) Thread Form , r = Basic Radius = * 137329 p , h = Basic Depth of Thread = *640327 p , p = Pitch = 1/t.p.i. (Threads per Inch) , ISO 228, DIN 259, BS2779, JIS B0202 , In Japan this thread is known as (PF) , Use prefix G
How to distinguish M thread, G thread, R thread, Rc thread and Rp thread?
A male G thread and G thread together do not have sealing effect, it is mainly used in wire tube / cable tube which do not require sealing effect. (2) Sealing pipe thread, these kinds of thread have sealing effect after screwed. There are three types of sealing pipe threads: R thread: tapered male thread. Rc thead: tapered thread.
BSPT = British Standard Pipe Taper is an obsolete designation still in common usage which has been replaced with the R-Series. R = External tapered screw pipe thread for fits made on the thread per ISO-7 & BS-21. Per the standard the R mates with the Rc and Rp, but will also mate with the G. Rc = internal tapered threads for fits made on the