Hose and Hose Assemblies. JGB's Hose, Fitting, and Valves CatalogJGB Enterprises Inc. celebrates its 35 years. The owner, Jay G Bernhardt, founded the company in 1977 and  we have grown the company into a leading defense contractor and commercial supplier in hoses and fittings
Request a Quote
Search Website 

Coupling Identification

There are five coupling systems generally used for hydraulic connections today. They are identified geographically or by country as:

 

This section lists the origin and coupling style found in each country. Brief descriptions and dimensional data follows each coupling style.

Iron Pipe Thread Abbreviations
NNationalFFuels
PPipeSStraight Thread
TTapered ThreadMMechanical Joint

 


NPTF

This is a dry seal thread; the National pipe tapered thread for fuels. This is used for both male and female ends.

The NPTF male will mate with the NPTF, NPSF, or NPSM female.

The NPTF male has tapered threads and a 30° inverted seat. The NPTF female has tapered threads and no seat. The seal tales place by deformation of the threads. The NPSM female has straight threads and a 30° inverted seat. The seal takes place on the 30° seat.

The NPTF connector is similar to, but not interchangeable with, the BSPT connector. The thread pitch is different in most sizes. Also, the thread angle is 60° instead of the 55° angle found on BSPT threads.

NPSF

The National pipe straight thread for fuels. This is sometimes used for female ends and properly mates with the NPTF male end. However, the SAE recommends the NPTF thread in preference to the NPSF for female ends.

NPSM

National pipe straight thread for mechanical joint. This is used on the female swivel nut of iron pipe swivel adapters. The leak-resistant joint is not made by the sealing fit of threads, but by a tapered seat in the coupling end.

NPT Pipe Thread - Coupling Identification
NPT Pipe Thread

Dash SizeNominal Size in.No. Threads per InchFemale ThreadMale Thread
Thread I.D. in.Thread O.D. in.
-21/82723/6413/32
-41/41815/3235/64
-63/81819/3243/64
-81/2143/427/32
-123/41461/641 1/16
-16111 1/21 13/641 5/16
-201 1/411 1/21 17/321 43/64
-241 1/211 1/21 25/321 29/32
-32211 1/22 1/42 3/8

 


*37° Flare (JIC)

The society of Automotive Engineers (SAE) specifies a 37° angle flare or seat be used with high pressure hydraulic tubing. These are commonly called JIC couplings.

The JIC 37° flare male will mate with a JIC female only. The JIC male has straight threads and a 37° flare seat. The JIC female has straight threads and a 37° flare seat. The seal is made on the 37° flare seat.

Some sizes have the same threads as the SAE 45° flare. Carefully measure the seat angle to differentiate.

*Note: Some C5, C5E and Lock-On couplings may have dual machined seats (both 37° and 45° seats).

37 deg. Flare JIC - Coupling Identification
37° Flare JIC

Dash SizeNominal Size in.Thread SizeFemale Thread Male Thread
Thread I.D. in.Thread O.D. in.
-21/85/16-2417/645/16
-33/163/8-2421/643/8
-41/47/16-2025/647/16
-55/161/2-2029/641/2
-63/89/16-181/29/16
-81/23/4-1611/163/4
-105/87/8-1413/167/8
-123/41 1/16-1231/321 1/16
-147/81 3/16-121 7/641 3/16
-1611 5/16-121 15/641 5/16
-201 1/41 5/8-121 35/641 5/8
-241 1/21 7/8-121 51/641 7/8
-3222 1/2-122 27/642 1/2

 


*SAE (45° Flare)

A term usually applied to fittings having a 45° angle flare or seat. Soft copper tubing is generally used in such applications as it is easily flared to the 45° angle. These are for low pressure applications - such as for fuel lines and refrigerant lines.

The SAE 45° flare male will mate with an SAE 45° flare female only.

The SAE male has straight threads and a 45° flare seat. The SAE female has straight threads and a 45° flare seat. The seal is made on the 45° flare seat.

Some sizes have the same threads as the SAE 37° flare. Carefully measure the seat angle to differentiate.

*Note: Some C5, C5E, PCTS, C14, and Lock-On couplings may have dual machined seats (both 37° and 45° seats).

SAE 45 deg Flare - Coupling Identification
SAE 45° Flare

Dash Size Nominal Size in.Thread SizeFemale Thread Male Thread
Thread I.D. in.Thread O.D. in.
-21/85/16-2417/645/16
-33/163/8-2421/643/8
-41/47/16-2025/647/16
-55/161/2-2029/641/2
-63/85/8-189/165/8
-77/1611/16-165/811/16
-81/23/4-1611/163/4
-105/87/8-1413/167/8
-123/41 1/16-1463/641 1/16
-147/81 1/4-121 11/641 1/4
-1611 3/8-121 19/641 3/8

 

Special Power Steering Thread End

Dash SizeNominal Size in.Thread SizeFemale ThreadMale Thread
Thread I.D. in.Thread O.D. in.
3/811/1611/16-185/811/16

 


O-Ring Boss

The O-Ring boss male will mate with an O-Ring boss female only. The female is generally found on ports.

The male has straight threads and an O-Ring. The female has straight threads and a sealing face. The seal is made at the O-Ring on the male and the sealing face on the female.

SAE Straight Thread O-Ring Boss - Coupling Identification
SAE Straight Thread O-Ring Boss

Dash SizeNominal Size in.Thread SizeFemale
Thread
Male
Thread
"O"
Ring
Size
Thread I.D. in.Thread O.D. in.
-21/85/16-2417/645/16-
-33/163/8-2421/643/882500
-41/47/16-2025/647/1682501
-55/161/2-2029/641/282502
-63/89/16-181/29/1682503
-81/23/4-1611/163/482504
-105/87/8-1413/167/882505
-123/41 1/16-1231/321 1/1682506
-147/81 3/16-121 7/641 3/1682507
-1611 5/16-121 15/641 5/1682508
-201 1/41 5/8-121 35/641 5/882509
-241 1/21 7/8-121 51/641 7/8-
-3222 1/2-122 27/642 1/2-

 


O-Ring Flange - SAE J518

The SAE Code 61 and Code 62 4-Bolt Split Flange is used worldwide, usually as a connection on pumps and motors.

There are three exceptions:

1. The -10 size, which is common outside of North America, is not an SAE standard size.

2. Caterpillar flanges, which are the same flange O.D. as SAE Code 62, have a thicker flange head ("C" dimension in illustration).

3. Poclain flanges, which are completely different from SAE flanges.

O-Ring Flange - SAE J518 - SAE Code 61 and Code 62  - Coupling Identification
SAE Code 61 and Code 62

Nominal Flange SizeCode61 (FL)
Flange O.D.ABC
1/21.188.6881.500.265
5/81.338--.265
3/41.500.8751.875.265
11.7501.0312.062.315
1 1/42.0001.1882.312.315
1 1/22.3751.4062.750.315
22.8121.6883.062.375
2 1/23.3122.0003.500.375
34.0002.4384.188.375
3 1/24.5002.7504.750.422
45.0003.0625.125.442
56.0003.6256.000.442

 

Nominal Flange SizeCode62 (FLH)
Flange O.D.ABC
1/21.250.7181.594.305
3/41.625.9372.000.345
11.8751.0932.250.375
1 1/42.1251.2502.625.405
1 1/22.5001.4373.125.495
23.1251.7503.812.495

 

Nominal Flange SizeCaterpillar (FLC)
Flange O.D.ABC
3/41.625.9382.000.560
11.8751.0942.250.560
1 1/42.1251.2502.625.560
1 1/22.5001.4383.125.560
23.1251.7503.812.560

 


O-Ring Face Seal (ORFS) J1453

A seal is made when the O-ring in the male contacts the flat face on the female. Couplings are intended for hydraulic systems where elastomeric seals are acceptable to over cone leakage and leak resistance is crucial.

The solid male O-ring face seal fitting will mate with a swivel female O-ring face seal fitting only.

An O-ring rests in the O-ring groove in the male.

O-Ring Face Seal (ORFS) J1453 - Coupling Identification
O-Ring Face Seal

Dash SizeNominal Size in.Thread SizeMale
Thread
Female
Thread
"O"
Ring
Size
Thread O.D. in.Thread I.D. in.
-41/49/16-189/161/2-011
-63/811/16-1611/165/8-012
-81/213/16-1613/163/4-014
-105/81-14115/16-016
-123/41 3/16-121 3/161 1/8-018
-1611 7/16-121 7/161 11/32-021
-201 1/41 11/16-121 11/161 19/32-025
-241 1/22-1221 29/32-029

 


Flareless Tube

The flareless solid male will mate with a female flareless nut and compression sleeve only.

The male has straight threads and a 24 seat. The female has straight threads and has a compression sleeve for a sealing surface. The seal is made between the compression sleeve and the 24 seat on the male, and between the compression sleeve and the tubing on the female.

Flareless Tube - Coupling Identification
Flareless Tube

Dash SizeTube Size
in.
Nominal Size
in.
Thread Size Female ThreadMale Thread
Thread I.D. in.Thread O.D. in.
-21/85/165/16-2417/165/16
-33/163/83/8-2421/643/8
-41/47/167/16-2025/647/16
-55/161/21/2-2029/641/2
-63/89/169/16-181/29/16
-81/23/43/4-1611/163/4
-105/87/87/8-1413/167/8
-123/41 1/161 1/16-1231/321 1/16
-147/81 3/161 3/16-121 7/641 3/16
-1611 5/161 5/16-121 15/641 5/16
-201 1/41 5/81 5/8-121 35/641 5/8
-241 1/21 7/81 7/8-121 51/641 7/8
-3222 1/22 1/2-122 27/642 1/2

 


SAE Inverted Flare

The SAE 45° inverted flare male will mate with an SAE 42° inverted flare female only.

The male has straight threads and a 45° inverted flare. The female has straight threads and a 42° inverted flare. The seal is made on the 45° flare seat on the male and the 42° flare seat on the female.

SAE Inverted Flare - Coupling Identification
SAE Inverted Flare

Dash SizeNominal Size in.Thread SizeFemale ThreadMale Thread
Thread I.D. in.Thread O.D. in.
-21/85/16-289/325/16
-33/163/8-2421/643/8
-41/47/16-2425/647/16
-55/161/2-2029/641/2
-63/85/8-1837/645/8
-77/1611/16-185/811/16
-81/23/4-1645/643/4
-105/87/8-1813/167/8
-123/41 1/16-1611 1/16

 


Female Braze-On Stems

FBO / Female Braze-On Stems - Coupling Identification
Braze-On Stems
Dash Size Tubing O.D. "B" (inch)
-41/4
-55/16
-63/8
-81/2
-105/8
-123/4
-161
-201 1/4
-241 1/2

 


Grease Fittings

Special Male Grease Fitting - Coupling Identification
Special Male Grease Fitting

Special Female Grease Fitting - Coupling Identification
Special Female Grease Fitting

 


Parker Triple Thread Flare Fittings

Parker Triple Thread Flare Fittings - Coupling Identification
Parker Triple Thread Flare Fittings

Dash SizeNominal
Thread Size in.
Thread SizeMale ThreadFemale Thread
Thread O.D. in.Thread I.D. in.
-161 5/161 5/16-141 5/161 1/4
-201 5/81 5/8-141 5/81 9/16
-241 7/81 7/8-141 7/81 13/16
-322 1/22 1/2-122 1/21 1/4

 


Press-Lok Connectors

Press-Lok style connectors are found on mining equipment worldwide.

The seal is made when the O-ring on the male contacts the inside surface of the female. The two connectors are held together with a staple.

Press-Lok Connectors - Coupling Identification
Press-Lok Connectors

Dash
Size
Nominal
Size in.
Male ThreadFemale Thread
Thread
O.D. in.
Thread
I.D. in.
-41/4.39.40
-63/8.55.56
-81/2.70.71
-123/4.94.95
-1611.221.23
-201 1/41.491.50