NPT/NPS threads have a 60° included angle and have flattened peaks and valleys (this is a Sellers thread form); BSP threads have a 55° included angle and have rounded peaks and valleys (this is a Whitworth thread form). The flank angles of the threads are also different between NPT and BSP. male thread form into a BSP female straight thread form. Whitworth's new standard specified a 55° thread angle and a thread depth of 0.640327p and a radius of 0.137329p. Threads commonly used in Piping - Piping thread standards; Whitworth Pipe Threads - BSPP (G) - British Standard Pipe Parallel and BSPT (R/Rp) – British Standard Tapered Pipe for pipes and tapered threads - G/R/Rp; Withworth Threads - Taps and Drill Sizes - Taps and drill sizes used for Whitworth - ISO 7 and ISO 228 threads inch - TPI mm inch mm inch mm inch mm inch 1/8 - 28 -02 9.5 0.37 9.6 0.38 8.4 0.33 8.6 0.34 NPT and BSP thread pitches (threads per inch, TPI) are listed below. BSPT (R/Rp) – British Standard Tapered Pipe, for pipes and tapered thread; An appropriate sealing compound can be used in the thread to ensure a leakproof joint. Thick‐. BSPP FEMALE THREAD I.D. NOTE: It is a common mistake to identify a BSPT (tapered) as an NPT. BSPP MALE THREAD O.D. British Standard Pipe Taper (BSPT) Threads Size Chart. Remember that NPT threads have a 60° thread flank angle, and BSPT has a 55° angle (this can be verified with a thread gauge). ness [mm] 1/16 28 0.907 7.723 0.304 4 1/8 28 0.907 9.728 0.383 4 6 10.2 0.4 2 1/4 19 1.337 13.157 0.518 6 8 13.5 0.53 2.3 3/8 19 1.337 16.662 0.656 6.4 10 17.2 0.68 2.3 1/2 14 1.814 20.995 0.825 8.2 15 21.3 0.84 2.6 5/8 14 1.814 22.911 0.902 16 2.6 3/4 14 1.814 26.441 1.041 9.5 20 26.9 … BSPP male and BSPP female flat face swivel require a suitable soft washer between faces to seal. d3: Thread Height H1: Tap Drill Diameter mm: G1/8 : 1/8" BSPP: 9.728: 0.907: 28: 9.147: 8.566: 0.581: 8.70: G1/4 : 1/4" BSPP: 13.157: 1.337: 19: 12.301: 11.445: 0.856: 11.60: G3/8 : 3/8" BSPP: 16.662: 1.337: 19: 15.806: 14.950: 0.856: 15.00: G1/2 : 1/2" BSPP: 20.955: 1.814: 14: 19.793: 18.631: 1.162: 19.00: G5/8 : 5/8" BSPP: … 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. British Standard Pipe Taper (BSPT) Threads Size Chart. Tap Drill Charts | British Standard Pipe Threads. Thread Identifying Tools You Need Caliper – A caliper is a useful tool that measures the outside diameter of a male thread and inside diameter of a female thread. Where p is the pitch. BSPT & BSPP SIZE & PITCH DASH SIZE BSPT MALE THREAD O.D. NPT has a 60° thread where the BSP has a 55° thread. External Pipe Threads per. The 1/16”, 1/8”, 1/4”, and 3/8” sizes have a dissimilar pitch, which causes a misalignment of the threads. The thread pitch increases with the diameter in steps specified on a chart. Threads per inch: Pitch Diameter mm d2=D2: Minor Diameter Male Thd. BSPT FEMALE THREAD I.D. (Threads per Inch) ISO 228, DIN 259, BS2779, JIS B0202 In Japan this thread is known as (PF) Use prefix G for parallel thread. Figure 5 shows a male NPT tightened into a BSPP. The thread flank angle for both tapered and parallel British threads is 55°. For low working pressure. ISO 228-1, Pipe threads where pressure-tight joints are not made by the threads. NPT/NPTF Thread Type Chart BSP Thread Type Chart PT Thread Type Chart SAE Thread Type Chart Metric Thread Type Chart Thread Seal Tape and Alternative Solutions. Thread Chart for British Standard Pipe Threads BSP, BSPP (Parallel Thread), BSPT (Taper Thread), Nominal Size, Thread per Inch, Depth of Thread, Major Diameter, Pitch Diameter, Minor diameter. The Whitworth thread system was later to be adopted as a British Standard to become British Standard Whitworth (BSW). If you have any questions please contact us or check out our fittings with BSPP/ BSPT (G) thread. BSW BSPP BSPT Pipe Tap Size Pitch (TPI) Drill Size (inch) Pitch (TPI) Drill Size (inch) Pitch (TPI) Drill Size* (inch) 1/16 60 0.046 (#56) 28 0.261 (G) - - 1/8 40 0.098 (#40) 28 11/32 28 21/64 1/4 20 0.196 (#9) 19 29/64 19 7/16 5/16 18 1/4 - - - - 3/8 16 5/16 19 19/32 19 37/64 7/16 14 23/64 - - - - 1/2 12 0.413 (Z) 14 3/4 14 23/32 9/16 12 17/32 - - - - 5/8 11 35/64 14 53/64 … These pipe threads are also known as Whitworth pipe threads. Where: D = Major Dia.internal thread D 1 = Minor Dia.internal thread D 2 = Pitch diameter internal thread d = Major Dia.external thread d 1 = Minor Dia.external thread Although BSP is a foreign thread…