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. Tap Drill Charts | British Standard Pipe Threads. Thick‐. 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 … male thread form into a BSP female straight thread form. Figure 5 shows a male NPT tightened into a BSPP. 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. NOTE: It is a common mistake to identify a BSPT (tapered) as an NPT. BSPT & BSPP SIZE & PITCH DASH SIZE BSPT MALE THREAD O.D. Whitworth's new standard specified a 55° thread angle and a thread depth of 0.640327p and a radius of 0.137329p. BSPT FEMALE THREAD I.D. Although BSP is a foreign thread… BSPP FEMALE THREAD I.D. NPT and BSP thread pitches (threads per inch, TPI) are listed below. NPT has a 60° thread where the BSP has a 55° thread. 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). If you have any questions please contact us or check out our fittings with BSPP/ BSPT (G) thread. Remember that NPT threads have a 60° thread flank angle, and BSPT has a 55° angle (this can be verified with a thread gauge). 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. BSPP male and BSPP female flat face swivel require a suitable soft washer between faces to seal. Threads per inch: Pitch Diameter mm d2=D2: Minor Diameter Male Thd. External Pipe Threads per. 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 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. BSPP MALE THREAD O.D. These pipe threads are also known as Whitworth pipe threads. British Standard Pipe Taper (BSPT) Threads Size Chart. British Standard Pipe Taper (BSPT) Threads Size Chart. 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 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 Where p is the pitch. 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 … The Whitworth thread system was later to be adopted as a British Standard to become British Standard Whitworth (BSW). 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. The 1/16”, 1/8”, 1/4”, and 3/8” sizes have a dissimilar pitch, which causes a misalignment of the threads. 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: … For low working pressure. ISO 228-1, Pipe threads where pressure-tight joints are not made by the threads. The thread pitch increases with the diameter in steps specified on a chart. The flank angles of the threads are also different between NPT and BSP. The thread flank angle for both tapered and parallel British threads is 55°. (Threads per Inch) ISO 228, DIN 259, BS2779, JIS B0202 In Japan this thread is known as (PF) Use prefix G for parallel thread.