what is O-Ring Face Seal ORFS(SAE J1453)

O-Ring Face Seal (ORFS) threads, standardized by SAE J1453 and ISO 8434-3, offer a reliable and efficient sealing solution for hydraulic systems.This connection forms an impressive leak resistance and can be used in applications up to 6000 psi. The male half of the connection has an O-ring with a straight thread. The female half has a machinedflat surface with a straight thread. A seal takes place when the O-ring on the male end is squeezed onto the female flat surface seat. The swivel nut on the female half holds the connection together.

Key Features:

  • O-ring seal:The seal is created by a precisely positioned O-ring, housed within a groove on the male fitting, that compresses against a flat sealing surface on the female fitting.
  • Straight threads:ORFS fittings use straight threads, eliminating the need for thread sealants and easing assembly.
  • High-pressure capability:They can withstand very high pressures, typically up to 6000 PSI, making them suitable for demanding applications.
  • Reusability:The O-ring can be replaced, enabling multiple reuses of the fitting.Swivel nut design:The female fitting often features a swivel nut that allows for easier alignment and tightening in tight spaces.


  • Hydraulic systems:Widely used in hydraulic systems due to their leak-proof reliability and ease of use.
  • High-pressure applications:Ideal for applications involving high pressures, such as industrial machinery, construction equipment, and power systems.
  • Fluid power systems:Commonly found in fluid power systems in various industries, including manufacturing, agriculture, and aerospace.
  • Off-road vehicles:Frequently used in off-road vehicles and heavy equipment for their durability and resistance to vibration and harsh conditions.
  • Oil and gas industry:Employed in oil and gas applications due to their ability to handle high pressures and temperatures.


  • Leak-proof seal:The O-ring provides a secure and leak-proof seal, even under high pressure and vibration.
  • Ease of assembly:Straight threads and swivel nut design simplify installation and maintenance.
  • High-pressure capability:Can handle very high pressures, meeting the demands of various industries.
  • Reusability:Replacing the O-ring extends fitting life and reduces maintenance costs.
  • Resistance to vibration:The O-ring helps absorb vibration, ensuring a secure connection in harsh environments.

O-Ring Face Seal threads offer a highly reliable and efficient sealing solution for various hydraulic and fluid power systems, making them a popular choice in industries where leak-proof connections, ease of assembly, and high-pressure capability are paramount.

drawing ORFS

Inch size Dash size Thread Size Male Thread O.D. (in) Female thread O.D (in)
14 -4 916– 18 916 0.56 1732 0.51
38 -6 1116– 16 1116 0.69 58 0.63
12 -8 1316– 16 1316 0.82 34 0.75
58 -10 1 – 14 1 1.00 1516 0.93
34 -12 1316– 12 1316 1.19 118 1.11
1 -16 1716– 12 1716 1.44 134 1.36
114 -20 11116– 12 11116 1.69 158 1.61
112 -24 2-12 2 2.00 11516 1.92

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