Parker Hannifin Corporation
Fluid System Connectors
Otsego, Michigan
N10
Catalog 3501E
General Technical
Abbreviation
Description
Applicable Std.
Metric Threads
M
Metric Screw Threads — M profile
ISO 261
ANSI B1.13M
FED-STD-H28/21
M — Keg
Metric Taper Threads (mainly used in Germany)
DIN 158
British Standard
Pipe Threads
R (BSPT)
British Standard Taper Pipe Threads, External
BS 21
ISO 7/1
Rc (BSPT)
British Standard Taper Pipe Threads, Internal
BS 21
ISO 7/1
Rp or G (BSPP)
British Standard Pipe (Parallel) Threads
BS 2779
ISO 228/1
Japanese Standard
Pipe Threads
PF
1)
JIS Parallel Pipe Threads
JIS B202
ISO 228/1
PT
1)
JIS Taper Pipe Threads
JIS B203
ISO 7/1
PS
JIS Parallel Internal Pipe Threads (to mate with PT threads)
JIS B203
Table A48 (Cont'd) — Thread Designations and Standards for Threads Used in Fluid Connectors
1)
PF and PT threads are functionally interchangeable with BSPP and BSPT threads, respectively.
These are old designations. They are being replaced with G (for PF) and R and Rc (for PT) as documents are revised.
Straight Thread Size Comparison Chart
TUBE O.D.
1/8
3/16
1/4
5/16
3/8
7/16
1/2
5/8
3/4
7/8
1
SAE 45°Flared
5/16
-24
3/8
-24
7/16
-20
1/2
-20
5/8
-18
11/16
-16
3/4
-16
7/8
-14
1-1/16
-14
1-1/4
-12
-
Inverted Flared
5/16
-28
3/8
-24
7/16
-24
1/2
-20
5/8
-18
11/16
-18
3/4
-18
7/8
-18
1-1/16
-16
1-3/16
-16
-
Air Brake/NTA
-
-
7/16
-24
-
17/32
-24
-
11/16
-20
13/16
-18
1
-18
-
1-1/4
-16
Standard.
Compression /
Compress-Align
5/16
-24
3/8
-24
7/16
-24
1/2
-24
9/16
-24
5/8
-24
11/16
-20
13/16
-18
1
-18
1-1/8
-18
1-1/4
-18
Poly-Tite
3/8
-24
7/16
-24
1/2
-24
-
11/16
-20
-
-
-
-
Vibra-Lok
3/8
-24
-
1/2
-24
9/16
-24
5/8
-24
-
13/16
-18
1
-18
1-1/8
-18
-
-
V510 Ball Valves
-
-
7/16
-20
-
9/16
-18
-
3/4
-16
7/8
-14
1-1/16
-12
-
1-5/16
-12
Hi-Duty Flareless
Tube Fittings
5/16
-24
3/8
-24
7/16
-20
1/2
-20
9/16
-20
-
11/16
-16
7/8
-18
-
-
-