NPT & NPSM Thread Identification
NPT – National Pipe Taper – ANSI/ASME B1.20.1-1983
NPSM – National Pipe Straight Mechanical – ANSI/ASME B1.20.1-1983
| Dash Size |
Thread Size – Threads Per Inch |
NPT Male Thread Size |
NPT Fixed Female Thread Size |
NPSM Female Swivel Thread Size |
|||
|---|---|---|---|---|---|---|---|
| usa | Size – TPI | mm | Inch | mm | Inch | mm | Inch |
| -2 | 1/8 – 27 | 9.89 | 0.39 | 8.41 | 0.33 | 8.59 | 0.34 |
| -4 | 1/4 – 18 | 13.19 | 0.52 | 11.21 | 0.44 | 11.89 | 0.47 |
| -6 | 3/8 – 18 | 16.61 | 0.65 | 14.69 | 0.58 | 14.99 | 0.59 |
| -8 | 1/2 – 14 | 20.61 | 0.81 | 17.79 | 0.71 | 19.09 | 0.75 |
| -12 | 3/4 – 14 | 26.01 | 1.02 | 23.39 | 0.92 | 24.59 | 0.97 |
| -16 | 1 – 11.5 | 32.49 | 1.28 | 29.49 | 1.16 | 30.49 | 1.2 |
| -20 | 1.1/4 – 11.5 | 41.21 | 1.62 | 38.09 | 1.5 | 39.39 | 1.55 |
| -24 | 1.1/2 – 11.5 | 47.31 | 1.85 | 43.89 | 1.73 | 45.51 | 1.79 |
| -32 | 2 – 11.5 | 59.29 | 2.32 | 56.39 | 2.22 | 57.41 | 2.26 |
* Thread size refers to the nominal bore of the pipe.
Subtract approx. 1/4″ (6mm) from thread diameter measurement for nominal pipe size.
NPT – NPT : NPT to fixed NPT female sealing is made through direct metal to metal contact. The use of Volz Thread Sealant is recommended.
NPT – NPSM : NPT male with conical 30° seat (60° included angle) seal against matching conical 30° seat of NPSM female swivel.
BSPP & BSPT Thread Identification Table
BSPP & BSPT Thread Identification Table
BSP – BRITISH STANDARD PIPE
BSPT – BRITISH STANDARD PIPE TAPER DIN 3852-1+2
BSPP – BRITISH STANDARD PIPE PARALLEL ISO 1179-1,DIN 3852 T2
| Dash Size |
Thread Size – Threads Per Inch |
BSPP Male Thread Size |
BSPP Female Thread Size |
BSPT Male Thread Size |
BSPT Female Thread Size |
||||
|---|---|---|---|---|---|---|---|---|---|
| usa | Size – TPI | mm | Inch | mm | Inch | mm | Inch | mm | Inch |
| -2 | 1/8″ – 28 | 9.59 | 0.38 | 8.6 | 0.34 | 9.51 | 0.37 | 8.49 | 0.33 |
| -4 | 1/4″ – 19 | 13.01 | 0.51 | 11.9 | 0.47 | 12.78 | 0.5 | 11.19 | 0.44 |
| -6 | 3/8″ – 19 | 16.49 | 0.65 | 15.2 | 0.6 | 16.31 | 0.64 | 14.68 | 0.59 |
| -8 | 1/2″ – 14 | 20.79 | 0.82 | 19.1 | 0.75 | 20.39 | 0.8 | 18.32 | 0.72 |
| -10 | 5/8″ – 14 | 22.81 | 0.9 | 20.8 | 0.82 | 22.51 | 0.89 | 20.59 | 0.81 |
| -12 | 3/4″ – 14 | 26.31 | 1.04 | 24.6 | 0.97 | 25.91 | 1.02 | 23.91 | 0.94 |
| -16 | 1″ – 11 | 33.09 | 1.3 | 30.7 | 1.21 | 32.59 | 1.28 | 29.71 | 1.17 |
| -20 | 1.1/4″ – 11 | 41.79 | 1.64 | 39.4 | 1.55 | 41.09 | 1.62 | 38.59 | 1.52 |
| -24 | 1.1/2″ – 11 | 47.69 | 1.88 | 45.5 | 1.79 | 47.01 | 1.85 | 44.49 | 1.75 |
| -32 | 2″ – 11 | 59.51 | 2.34 | 57.4 | 2.26 | 58.6 | 2.31 | 56.39 | 2.22 |
* Thread size refers to the nominal bore of the pipe.
Subtract approx. 1/4″ (6mm) from thread diameter measurement for nominal pipe size.
BSPP : BSPP male with conical 30° seat (60° included angle) seal against matching conical 30° seat of BSPP female swivel.
BSPP – Form B – Seals using a metal to Metal sealing Edge.
BSPP – Form E – Seals using a Elastomer Seal (Volz WD Seal)
BSPP – Form B can also be used with Captive O-rings or Encapsulated Seals for Chamfered Female Ports or for your preference.
BSPP Positional Elbows and tees have Lock Nut and O ring to allow orientation of fitting to required direction.
BSPT : BSPT male threads seal against threads of a fixed BSPT female.
Contact is made on the flanks of the threads.
Use of Volz thread sealant or Thread Lubricant is recommended for BSPT male to BSPT female connections.
Compatability: Please ring for more information about interchangeability
JIC 37 Degree Flare & UNO (O-Ring Boss)
JIC 37 Degree Flare & UNO (O-Ring Boss)
| Thread Size |
Dash Size |
Male Thread O.D |
Female Thread I.D |
Tube Size | Pressure Ratings (Bar) |
Threads Per Inch |
|
|---|---|---|---|---|---|---|---|
| inch | usa | mm | mm | inch | Male | Female | TPI |
| 7/16 | -4 | 11.0 | 10 | 1/4 | 550 | 550 | 20 UNF |
| 1/2 | -5 | 12.5 | 11.5 | 5/16 | 550 | 500 | 20 UNF |
| 9/16 | -6 | 14.2 | 13 | 3/8 | 500 | 420 | 18 UNF |
| 3/4 | -8 | 18.9 | 17.5 | 1/2 | 500 | 420 | 16 UNF |
| 7/8 | -10 | 22.1 | 20.3 | 5/8 | 450 | 400 | 14 UNF |
| 1.1/16 | -12 | 26.8 | 25.1 | 3/4 | 420 | 350 | 12 UN |
| 1.5/16 | -16 | 33.2 | 31.5 | 1 | 300 | 250 | 12 UN |
| 1.5/8 | -20 | 41.1 | 39.5 | 1.1/4 | 250 | 210 | 12 UN |
| 1.7/8 | -24 | 47.5 | 45.6 | 1.1/2 | 220 | 180 | 12 UN |
| 2.1/2 | -32 | 63.4 | 61.5 | 2 | 150 | 150 | 12 UN |
JIC – Joint Industry Council – SAE J514, ISO 8434-2
UN – Unified National – SAE J1926, ISO 11926-2
JIC & UNO (O Ring Boss) thread forms are the same (ASME B1.1). Method of sealing differs
JIC : Male has a 37° Seat. This seat is the sealing face (face that stops the leaks). When screwed into a JIC Female the 37° Male seat will seal up against the 37° seat of the female.
For joining tube together or to adapt a tube to another fitting – A JIC Tube nut + Sleave can be used. The tube will need flaring to 37°, the end result is a female JIC end.
UNO (O-Ring Boss) : Although the thread is the same as JIC, the sealing method is different. All UNO male’s will have an O-Ring, this O-ring is the seal, it will sit in the female port spot face. For Elbows and Tee’s there is an added backup washer and lock nut on the fittings to allow for different orientation.