Society of Automotive Engineers Thread (SAE)

SAE J1926 Straight Thread O-Ring Boss (ORB) is recommended by the National Fire Protection Association (N.F.P.A.) for leak prevention in medium and high pressure hydraulic systems.

The male connection is a straight thread with an O-ring. The female port has a straight thread and a machined surface to provide a smooth, flat surface (minimum spotface), along with a chamfer where the O-ring seats. It seals when the O-ring is compressed into the chamfer when mating the male connection. This is also considered a mechanical connection.

SAE J514 JIC/37° Hydraulic connections are common in most fluid power systems. Both male and female components have 37° seats. The seal is made by establishing contact between the male flared and female coned seat. This is also considered a mechanical connection.

SAE J512 45° connections are used in automotive, refrigeration and truck pipe systems. These connectors are typically brass material. The male and female connections have 45° seats, where the seal is make where the male flare and the female cone meet. This is a mechanical connection also.

NOTE dash sizes: -02, -03, -04, -05, -08, and -10 of SAE 37° and SAE 45° have the same threads, but NOT the same seat angles. Intermixing the two different types of fittings will result in leakage, so use care in measuring seat angles.

SAE J1453 (ORFS) O-ring Face Seal connections are considered the best for leak control. The male connector has a straight thread and an O-ring in the face.

The female has a straight thread and a machined flat face. The seal takes place by compressing the O-ring onto the flat face of the female, similar to the split flange type fitting. The threads maintain the connection mechanically.

SAE J512 Inverted connections are typically used in automotive systems. The male connector is either a 45° flare within the tube fitting or a 42° seat in the machined adapter.

The female incorporates a straight thread with a 42° inverted flare. The fittings are sealed at the flared surfaces. These threads also maintain a mechanical connection.

SAE J518 4-Bolt Flange* There are two pressure ratings for these connections: Code 61 which is considered the standard series and Code 62 which is the 6000 PSI series.

The design is the same for each series, yet the flange head diameters and bolt hole spacing are larger for the 6000 PSI high pressure Code 62 connection.


The female port of the fitting is a smooth, un-threaded port with four bolt holes set in a rectangular pattern around the port. The male is a flanged head with a groove for an O-ring and either split or captive flange halves and bolt holes which match the port.

The seal is made where the O-ring is compressed between the flanged head and the flat surface of the port. The connection is held by threaded bolts.

*Excluding bolt sizes, SAE J518, JIS B 8363, ISO/DIS 6162 and DIN 20066 are interchangeable.


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