Whitworth Pipe Threads - Hahnreiter

1 1 ISO 7/1 DIN 2999BS 21 DIN ISO 228 part 12) pipe Threads where pressure tightWhitworth pipe Threads for threadedPipe Threads for tubes and fittingsPipe Threads where pressure-tight2joints are made on the pipes and fittings where pressure tight joints are madejoints are not made on the threadsthreadson the threadssealing on the threadsealing on the threadsealing on the threadnot sealing on the thread3internal threadexternal threadinternal threadexternal thread internal threadexternal threadinternal and external limit plug taper limit ring taper limit plug cylindrical limit taper limit plug taper limit ring cylindrical Go / No Go plug gaugegauge - gauge.

2 Gauge - ring gauge - gauge - gauge - cyl. Go ring gauge tolerance A or BISO 7/21) ISO 7/21) DIN 2999-4 DIN 2999-5 BS 21BS 21 DIN ISO 228 part 2 pipe ThreadsWhitworth pipe ThreadsUsing Whitworth pipe Threads it has to be distinguished between those Threads which are thought to be sealing on thethread and those which produce a mechanical connection without sealing Threads which are sealing on the thread are specified in various national and international standards. Basicthread dimensions are common for all Threads mentioned below. ISO 7/1 and BS 21 do not only specify the connectionof cylindrical internal and taper external thread as DIN 2999 does, but in addition define a taper internal thread (taper1 : 16).

3 Gauging systems for all three Threads differ and may lead to different results and thread connection given in DIN ISO 228 is notmeant to be sealing on the thread . Basic thread dimen-sions and pitch is common to the sealing thread2title of standard5short sign for thread3kind of connection6kind of ISO 7/2 specifying the appropriate gauges is subject to general ISO 228 has replaced DIN 259( Whitworth pipe Threads - cylindrical internal and external Threads ). For the cylindrical internal and externalthread short sign R has been applied, which could have led to confusion, because the same short sign is used for the taper external threadof DIN 2999 or ISO 7/1. Compared to DIN ISO 228 there are no differences between the Threads but some minor differences between for internal Whitworth pipe threadsand )

4 Hahnreiter taps are being produced withcloser tolerance Pitch- Minor- [TPI] [mm]d = Dd2= D2d1= D1G1/16280,9077,7237,1426,5611/8280,9079 ,7289,1478,5661/4191,33713,15712,301 11,4453/8191,33716,66215,806 14,9501/2141,81420,95519,793 18,6315/8141,81422,91121,749 20,5873/4141,81426,44125,279 24,1177/8141,81430,20129,039 27,8771112,30933,24931,770 30, ,30937,89736,418 34, ,30941,91040,431 38, ,30947,80346,324 44, ,30953,74652,267 50,7882112,30959,61458,135 56, ,30965,71064,231 62, ,30975,18473,705 72, ,30981,53480,055 78,5763112,30987,88486,405 84, ,309 100,33098,851 97,3724112,309 113,030 111,551 110,072a Tolerances of Toleran. ofinternal thread external / Rcpitch- turns turnsmmR[mm]1/164 0,071 1 0,91/84 0,071 1 0,91/46 0,104 1 1,33/86,4 0,104 1 1,31/28,2 0,142 1 1,83/49,5 0,142 1 1,8110,4 0,18 1 2, ,7 0,18 1 2, ,7 0,18 1 2,3215,9 0,18 1 2, ,5 0,217 3,5320,6 0,217 3,5425,4 0,217 3,5 NPTD PPE1L1L1L2L3(3 Turns)

5 L5[mm][TPI][mm] -pitch [mm][Gg] [mm][mm][mm]1/167,938270,9417,1424,064 4,326,6322,8224,7501/810,287270,9419,489 4,102 4,366,7032,8224,8211/413,716181,41112,48 75,786 4,10 10,2064,2347,3843/817,145181,41115,9266, 096 4,32 10,3584,2347,5361/221,336141,81419,7728, 128 4,48 13,5565,4439,9293/426,670141,81425,1178, 611 4,75 13,8615,44310,234133,40111,52,20931,461 10,164,60 17,3436,62712, ,16411,52,20940,218 10,668 4,83 17,9536,62713, ,26011,52,20946,287 10,668 4,83 18,3776,62713,960260,32511,52,20958,3251 1,074 5,01 19,2156,62714, ,02583,17570,159 17,323 5,46 28,8926,35022,542388,90083,17586,068 19,456 6,13 30,4806,35024, ,60083,17598,776 20,853 6,57 31,7506,35025,4004114,30083,175111,433 21.

6 438 6,75 33,0206,35026,670 pipe ThreadsAmerican pipe Threadspipe threadexternal threadinternal threadremarksNPT general purpose tapertaperNPTFdry sealingtapertaperNPSCC=coupling general purpose taper (NPT)cylindricalprofile as NPTNPSMM=mechanicalfastening threadcylindricalcylindricalUN- thread profileNPSFdry sealingtaper (NPTF)cylindricalprofile as NPTFNPSIdry sealingtaper (NPT-SAE / cylindricalthread diameter slightly increased with,NPTF)same width of tolerance fieldNPSLL=Locknutcylindricalcylindrical The difference between thread profile of NPT and NPTF Threads is the width of flat of profile on the outside and minordiameter. NPTF thread has got an overlap of profiles of internal and external thread . By this method, drysealing property is achieved.

7 Compared to the NPT, NPTF is one thread longer on L1+ L3and , NPSC-, NPSM- and NPSL- thread are defined in ANSI/ASME , NPTF, NPSF and NPSI- thread are given in ANSI of NPT-threadDoutside- of pipeL3wrenching allowanceE1pitch- at length L1L4length of external threadL1position of handtight engagementL5external thread with complete thread profile(on the length of 2 P beyond L5external thread profile is incomplete at the topof the Threads because the cone of thread profile meets the cylindrical outsidediameter of the pipe )L2useful external threadvincomplete thread produced by the chamfer of thread cutting toolNPTNPTFP[TPI]width of flat of profilewidth of flat of profile height of profileground ,0360,1040,6340,7530,1020,1520,0510,1021 80,0530,1450,9741,1290,1270,1780,0760,12 7140,0690,1631,2881,4510,1270,1780,0760, 12711 1/20,0840,1851,5901,7670,1520,2290,1020, 15280,1220,2292,3562,5400,2030,2790,1520 ,203