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Comparison Sheet for Thread Process Connections:  M – BSPP – BSPT – NPT – UNC – UNF

COMPARISON SHEET (M – BSPP – BSPT – NPT – UNC - UNF)
UNC (2A)
Metric: Standard/FineInch: BSPP (G)BSPT (R)NPTUNC/UNF
TypeParallelParallelTaperedTaperedParallel
Flank angle60°55°55°60°60°
Thread angle1°47’1°47’
Seal locationO-ring/ Gasket/ConeO-ring/ Gasket/ConeOn threadsOn threadsO-ring/ Gasket/Cone
COMPARISON SHEET (M – BSPP – BSPT – NPT – UNC - UNF)
Major Diameter (mm):
BSPP (G)BSPT (R/Rp)NPTUNCUNF
1/16”7,7237,7237,938
1/8”9,7289,72810,287
1/4”13,15713,15713,7166,3226,325
3/8”16,66216,66217,1459,4919,497
1/2”20,95520,95521,33612,66112,667
3/4”26,44126,44126,67019,00419,012
1”33,24933,24933,40125,34925,354
2”59,61459,61460,32550,726-
Minor Diameter (mm):
BSPP (G)BSPT (R/Rp)UNCUNF
1/16”6,5616,490
1/8”8,5668,495
1/4”11,44511,3414,9785,360
3/8”14,95014,8467,7988,382
1/2”18,63118,48910,59211,328
3/4”24,11723,97516,30717,323
1”30,29130,11121,97123,114
2”56,65656,47644,679-
TPI (Treads per inch):
BSPP (G)BSPT (R/Rp)NPTUNCUNF
1/16”282827
1/8”282827
1/4”1919182028
3/8”1919181624
1/2”1414141320
3/4”1414141016
1”111111,5812
2”111111,54,5-

How to Choose Thread Process Connections

There are no criteria to judge which Thread Process Connections mentioned above is better. Actually, each of them appears at a proper time with a proper reason. When it comes to choose a process connection, what really matters is the pipe fitting your pressure transducer is to be used.  It is true that different country has its own standards and it is also a fact that any thread standard is available worldwide.

If you need help in finding what your need. Contact Us! We are always ready to give your support in choosing pressure sensor Thread Process Connections.

Thread Permissible maximum pressure
Cu-alloyStainless steelMonel®
bar
psi
bar
psi
bar
psi
BSP ⅛ (G⅛)4006,00040060004006,000
BSP ¼ (G¼)6008,6001,00015,0001,00015,000
BSP ⅜(G⅜)6008,6001,00015,0001,00015,000
BSP ½ (G½)1,00015,0002,50036,0002,50036,000
M10 x 14006,0004006,0004006,000
M12 x 1.54006,0004006,0004006,000
M20 x 1.51,00015,0002,50036,0002,50036,000
⅛ NPT, R ⅛4006,0004006,0004006,000
¼ NPT, R ¼6008,6001,00015,0001,00015,000
⅜ NPT, R ⅜6008,6001,00015,0001,00015,000
½ NPT, R ½1,00015,0001,60023,0001,60023,000
7/16-20 UNF4006,00080012,00080012,000
The specified values for the maximum pressure are rounded values and are assigned to the nearest standard scale range.
Thread Glossary
ASMEThe American Society of Mechanical Engineers (ASME)
BSPPBritish Standard Pipe Parallel per ISO 228/1
BSPTBritish Standard Pipe Tapered per EN 10226-1. See ISO 7/1.
DINDeutsche Institut für Normung e.V.
ISO 228/1International Standards Organization Specification 228/1, straight threads, reference specification: BSPP, DIN 259, JIS B0202.
JISJapanese Industrial Standard
MetricISO Metric thread is a globally standardized thread
NPTNational Pipe Tapered.
SAESociety of Automotive Engineers
UNUnified Constant-Pitch Thread Series
UNC/UNRCUnified Coarse Thread Series
UNEF/UNREFUnified Extra-Fine Thread Series
UNF/UNRFUnified Fine Thread Series
UNRMale Screw Thread only
UNS/UNRSSelected special combinations of diameter, pitch, and length of engagement
PitchFor the purposes of this guide, pitch refers to threads per inch, instead of the distance between the threads, for fractional screw threads and pipe threads. For all metric screw threads, pitch refers to the distance between adjacent threads.

For the previous knowledge, please refer to Part 1.