WHAT THREAD IS IT?
NOTE: Parts shown are BARE-Co parts - original part numbers are shown for reference only.
Type of Seat on Fitting
Description
Thread
O.D.
(approx)
Threads
per
Inch
Imperial
Threads
Thread
to Order

BSP - most NON-US equipment
Male can be tapered thread BSPT (can seal on thread) or parallel BSPP (female always parallel)

NOTE: female hose swivel fittings will seal on either type with seat

* these
are
different
thread
forms
9.7mm (3/8"
28
1/8" BSP
13mm (1/2")
19
1/4" BSP
16.6mm (.653")
19
3/8" BSP
20.9mm* (.820")
14
1/2" BSP
26.4mm (1 1/32")
14
3/4" BSP
33mm (1 5/16")
11
1" BSP

NPT - most US equipment
Description as above

1/2" NPT will jam if mated with BSP.
NPT has sharper thread form
13mm (1/2")
18
1/4" NPT
16.8mm (.660")
18
3/8" NPT
21mm* (.827")
14
1/2" NPT
26.3mm (1.035")
14
3/4" NPT
33mm (1 5/16")
11 1/2"
1" NPT

JIC

UNF thread with 37° protruding seat on male fitting
1/2"
20
1/2" JIC
9/16"
18
9/16" JIC
3/4"
16
3/4" JIC
7/8"
14
7/8" JIC

UN-O-RING

UNF thread using O-Ring on male thread as seal
1/2"
20
1/2" UN-O-RING
9/16"
18
9/16" UN-O-RING
3/4"
16
3/4" UN-O-RING
7/8"
14
7/8" UN-O-RING
METRIC THREADS
Measure Thread O.D. and pitch (distance between threads) in mm
i.e. Typical FIAT thread 16mm x 1.5 pitch
WHAT THREAD IS IT?