{ "name": "Hydraulic and pipe connection type identification", "description": "Identifying characteristics of each hydraulic, pipe, and instrumentation connection standard used in fluid power and plumbing systems. For each connection type, gives the governing standard, seat or flare angle, whether the thread is tapered or parallel, how the seal is made, and interchangeability notes with other standards. Answers the recurring field question 'what kind of fitting is this?' \u2014 the identification step that must happen before any cross-reference or adapter lookup.", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/", "licence": "Factual compilation of connection type characteristics from a manufacturer's published identification guide. Individual facts (standard number, seat angle, thread type) are not copyrightable; short attributed quotes link back to the source page.", "last_verified": "2026-08-13", "stale_after": "2028-08-12", "sources": [ "https://brennaninc.com/connection-types/" ], "records": [ { "connection_type": "BSPP", "governing_standard": "BSP", "region": "British Connections", "thread_type": "parallel", "seat_angle": "cone seat", "seal_method": "A captive seal is made using metal to metal angled surfaces or a combination of metal to metal and an O-ring.", "interchangeability_notes": "very similar (but not interchangeable) with the American NPSM male", "id": "bspp", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/bspp/", "source": "https://brennaninc.com/connection-types/", "source_quote": "The British Standard Pipe Parallel (BSPP) male connection is comparable to NPSM male except most sizes have a different thread pitch. A captive seal is made using metal to metal angled surfaces or a combination of metal to metal and an O-ring. This type of connection is very similar (but not interchangeable) with the American NPSM male. The female swivel BSPP has a tapered nose flareless swivel where the seal occurs on the cone seat of the male connector.", "verified_fields": [ "connection_type", "interchangeability_notes", "seal_method", "seat_angle", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "BSPT", "governing_standard": "BSP", "region": "British Connections", "thread_type": "tapered", "seal_method": "Sealing takes place by distortion of the threads.", "interchangeability_notes": "comparable to NPT, except most sizes have a different thread pitch, plus the OD's and thread form are close, but not the same", "id": "bspt", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/bspt/", "source": "https://brennaninc.com/connection-types/", "source_quote": "British Connections British Standard Pipe (BSP) and British Standard Pipe Tapered (BSPT) connections are comparable to NPT, except most sizes have a different thread pitch, plus the OD\u2019s and thread form are close, but not the same. Sealing takes place by distortion of the threads. Because of this, thread sealants are recommended when securing these connections.", "verified_fields": [ "connection_type", "governing_standard", "interchangeability_notes", "seal_method", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "DIN 2353 / ISO 8434", "governing_standard": "DIN 2353 / ISO 8434", "region": "German Connections", "thread_type": "straight metric thread", "seat_angle": "24\u00b0", "seal_method": "The straight metric thread male has a 24\u00b0 angle. Its recessed counter-bore matches the tube O.D. it is connected to.", "id": "din-2353-iso-8434", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/din-2353-iso-8434/", "source": "https://brennaninc.com/connection-types/", "source_quote": "DIN 2353 / ISO 8434 series is a common male with three different possible female halves. The straight metric thread male has a 24\u00b0 angle. Its recessed counter-bore matches the tube O.D. it is connected to.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "DIN 3852", "governing_standard": "DIN 3852", "region": "German Connections", "thread_type": "straight metric thread", "seal_method": "DIN 3852 is a male connector and female port. It is a style controlled by German specifications.", "interchangeability_notes": "Other countries sometimes use it as a reference for connector and port designs.", "id": "din-3852", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/din-3852/", "source": "https://brennaninc.com/connection-types/", "source_quote": "DIN 3852 is a male connector and female port. It is a style controlled by German specifications. Other countries sometimes use it as a reference for connector and port designs.", "verified_fields": [ "connection_type", "governing_standard", "interchangeability_notes", "seal_method" ], "derived_fields": [ "region" ] }, { "connection_type": "DIN 7631", "governing_standard": "DIN 7631", "region": "German Connections", "thread_type": "straight metric thread", "seat_angle": "60\u00b0", "seal_method": "The male connector has a straight metric thread with a 60\u00b0 angle on the recessed cone. The female has a straight thread with a seat that is a tapered nose. The contact of the cone of the male and the tapered nose of the female flareless swivel is where the seal takes place.", "id": "din-7631", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/din-7631/", "source": "https://brennaninc.com/connection-types/", "source_quote": "DIN 7631 series is a common metric-style connection in hydraulic systems. The male connector has a straight metric thread with a 60\u00b0 angle on the recessed cone. The female has a straight thread with a seat that is a tapered nose. The contact of the cone of the male and the tapered nose of the female flareless swivel is where the seal takes place.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "Instrumentation Fittings (Double and Single Ferrule)", "governing_standard": "Instrumentation", "region": "Instrumentation Fittings", "thread_type": "UNEF (extra fine)", "seat_angle": "inner cone", "seal_method": "The seal is made between the front ferrule and the cone. The tubing is held in place by the swaging action caused by the tightening of the nut, which forces the front and back ferrules to bite into the tubing, firmly holding it in place.", "id": "instrumentation-fittings-double-and-single-ferrule", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/instrumentation-fittings-double-and-single-ferrule/", "source": "https://brennaninc.com/connection-types/", "source_quote": "Double and Single Ferrule Instrumentation Fittings are widely used in fluid or gas transfer applications such as refineries, chemical plants and food processing plants. The male end of a double-ferrule instrumentation fitting has a recessed counter-bore which matches the tube OD being used, plus an inner cone. The seal is made between the front ferrule and the cone. The tubing is held in place by the swaging action caused by the tightening of the nut, which forces the front and back ferrules to bite into the tubing, firmly holding it in place.", "verified_fields": [ "governing_standard", "seal_method", "seat_angle" ], "derived_fields": [ "region" ] }, { "connection_type": "ISO 6149", "governing_standard": "ISO 6149", "region": "ISO Connections", "thread_type": "straight threads", "seat_angle": "flat face", "seal_method": "The male connector has straight threads with an O-ring. The female port is also straight threads machined surface to provide a smooth, flat, accurately located 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.", "interchangeability_notes": "similar to the SAE J514 Straight Thread O-ring Boss (ORB), this type of connection incorporates metric threads", "id": "iso-6149", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/iso-6149/", "source": "https://brennaninc.com/connection-types/", "source_quote": "ISO 6149 Port and Stud Ends with ISO 261 Threads and O-ring Seal though it is similar to the SAE J514 Straight Thread O-ring Boss (ORB), this type of connection incorporates metric threads. The male connector has straight threads with an O-ring. The female port is also straight threads machined surface to provide a smooth, flat, accurately located 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.", "verified_fields": [ "connection_type", "governing_standard", "interchangeability_notes", "seal_method", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "ISO/DIS 6162 4-Bolt Flange", "governing_standard": "ISO/DIS 6162", "region": "ISO Connections", "thread_type": "flange bolts", "seat_angle": "flat surface", "seal_method": "The male is a flanged head with a groove for an O-ring to seat 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.", "interchangeability_notes": "Excluding bolt sizes, SAE J518, JIS B 8363, ISO/DIS 6162 and DIN 20066 are interchangeable.", "id": "iso-dis-6162-4-bolt-flange", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/iso-dis-6162-4-bolt-flange/", "source": "https://brennaninc.com/connection-types/", "source_quote": "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. JIS 210 Kgf/cm2 4-Bolt Square Flange incorporates a JIS 4-bolt square flange connection which is comparable to SAE 4-bolt flange connections with one difference \u2013 the flange itself is different and the JIS bolt pattern is square. ISO Connections ISO/DIS 6162 4-Bolt Flange is another common connection found in fluid power systems. There are two pressure ratings for this connection- Code 61: PN 35/350 bar which is considered the standard series and Code 62: PN 415 bar which is the high pressure series. They maintain the same design, yet with the bold hole spacings and flanged head diameters being larger on the PN 415 bar high pressure connection. Inch or metric bolts are found in these connections, however there is an \u201cM\u201d stamped on the port if metric bolts are to be used. The female port of the fitting is a smooth, un-threaded port with four bolt holes set in a rectangular pattern in around the port. The male is a flanged head with a groove for an O-ring to seat 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.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle" ], "derived_fields": [ "region" ] }, { "connection_type": "JIS 210 Kgf/cm2 4-Bolt Square Flange", "governing_standard": "JIS", "region": "Japanese Connections", "thread_type": "flange bolts", "seat_angle": "flat face", "seal_method": "JIS 210 Kgf/cm2 4-Bolt Square Flange incorporates a JIS 4-bolt square flange connection", "interchangeability_notes": "comparable to SAE 4-bolt flange connections with one difference \u2013 the flange itself is different and the JIS bolt pattern is square", "id": "jis-210-kgf-cm2-4-bolt-square-flange", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/jis-210-kgf-cm2-4-bolt-square-flange/", "source": "https://brennaninc.com/connection-types/", "source_quote": "JIS 210 Kgf/cm2 4-Bolt Square Flange incorporates a JIS 4-bolt square flange connection which is comparable to SAE 4-bolt flange connections with one difference \u2013 the flange itself is different and the JIS bolt pattern is square.", "verified_fields": [ "connection_type", "governing_standard", "interchangeability_notes", "seal_method" ], "derived_fields": [ "region" ] }, { "connection_type": "JIS 30\u00b0 Female (Cone) Seat", "governing_standard": "JIS B 0202", "region": "Japanese Connections", "thread_type": "parallel pipe threads", "seat_angle": "30\u00b0", "seal_method": "Japanese JIS 30\u00b0 flare connections are comparable to American SAE 37\u00b0 flare connections in application and sealing principals.", "interchangeability_notes": "JIS 30\u00b0 flare angle and dimensions are different with threads that are similar to BSPP", "id": "jis-30-female-cone-seat", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/jis-30-female-cone-seat/", "source": "https://brennaninc.com/connection-types/", "source_quote": "JIS 30\u00b0 Female (Cone) Seat connections are are parallel pipe threads per JIS B 0202. Japanese JIS 30\u00b0 flare connections are comparable to American SAE 37\u00b0 flare connections in application and sealing principals. Yet, JIS 30\u00b0 flare angle and dimensions are different with threads that are similar to BSPP.", "verified_fields": [ "connection_type", "governing_standard", "interchangeability_notes", "seal_method", "seat_angle", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "JIS 30\u00b0 Male Inverted Seat", "governing_standard": "JIS B 0202", "region": "Japanese Connections", "thread_type": "parallel pipe threads", "seat_angle": "30\u00b0", "seal_method": "JIS 30\u00b0 Male Inverted Seat connections are parallel pipe threads per JIS B 0202.", "interchangeability_notes": "JIS parallel connections are comparable to BSPP connections. JIS parallel thread connections are interchangeable with BSPP connections.", "id": "jis-30-male-inverted-seat", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/jis-30-male-inverted-seat/", "source": "https://brennaninc.com/connection-types/", "source_quote": "JIS 30\u00b0 Male Inverted Seat connections are parallel pipe threads per JIS B 0202. JIS parallel connections are comparable to BSPP connections. JIS parallel thread connections are interchangeable with BSPP connections.", "verified_fields": [ "connection_type", "governing_standard", "interchangeability_notes", "seal_method", "seat_angle", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "JIS B 8363 4-Bolt Flange", "governing_standard": "JIS B 8363", "region": "Japanese Connections", "thread_type": "flange bolts", "seat_angle": "flat surface", "seal_method": "The male connector has a flanged head with a groove for seating an O-ring and either a captive flange or split flange with bolt holes to correspond to 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.", "interchangeability_notes": "Excluding bolt sizes, SAE J518, JIS B 8363, ISO/DIS 6162 and DIN 20066 are interchangeable.", "id": "jis-b-8363-4-bolt-flange", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/jis-b-8363-4-bolt-flange/", "source": "https://brennaninc.com/connection-types/", "source_quote": "JIS B 8363 4-Bolt Flange connections are frequently used in fluid power systems. There are two pressure ratings for JIS B 8363 4-Bolt Flange fittings: Type I Code 61 is the standard series 4-Bolt Flange Type II Code 62 is the 6000 PSI series Each design concept is the same, yet the flanged head diameters and bolt hole spacing are larger for the Type II 6000 PSI connection. Metric and inch bolts are each used with these connectors. The male connector has a flanged head with a groove for seating an O-ring and either a captive flange or split flange with bolt holes to correspond to the port. The female port of the fitting is a smooth, un-threaded port with four bolt holes set in a rectangular pattern in around 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.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle" ], "derived_fields": [ "region" ] }, { "connection_type": "JIS Tapered Pipe (PT)", "governing_standard": "JIS B 0203", "region": "Japanese Connections", "thread_type": "tapered", "seal_method": "JIS Tapered Pipe (PT) has metric threads per JIS B 0203. These are JIS tapered threads and are comparable to the design of BSPT connections in their dimensions and appearance.", "interchangeability_notes": "JIS tapered thread connections are interchangeable with BSPT connections.", "id": "jis-tapered-pipe-pt", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/jis-tapered-pipe-pt/", "source": "https://brennaninc.com/connection-types/", "source_quote": "JIS Tapered Pipe (PT) has metric threads per JIS B 0203. These are JIS tapered threads and are comparable to the design of BSPT connections in their dimensions and appearance. JIS tapered thread connections are interchangeable with BSPT connections.", "verified_fields": [ "connection_type", "governing_standard", "interchangeability_notes", "seal_method", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "NPT", "governing_standard": "NPT", "region": "American Connections", "thread_type": "tapered", "seal_method": "NPT is a U.S. standard for tapered threads used on pipes and fittings. They are used to effectively seal pipes for fluid and gas transfer.", "id": "npt", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/npt/", "source": "https://brennaninc.com/connection-types/", "source_quote": "NPT (National Pipe Tapered) -style pipe threads have been widely used for over 100 years. NPT is a U.S. standard for tapered threads used on pipes and fittings. They are used to effectively seal pipes for fluid and gas transfer. The nominal pipe size can be identified by physically measuring the thread diameter, then subtracting 1/4\".", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "NPTF", "governing_standard": "NPTF", "region": "American Connections", "thread_type": "tapered thread", "seal_method": "They have a tapered thread by which a seal is made by deformation of the threads.", "id": "nptf", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/nptf/", "source": "https://brennaninc.com/connection-types/", "source_quote": "NPTF (National Pipe Tapered Fuel) -style connections are widely used in fluid power systems. They have a tapered thread by which a seal is made by deformation of the threads. NPTF Threads are measured at the thread diameter and subtracting 1/4-inch to establish the nominal pipe size.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "SAE J1453 (ORFS)", "governing_standard": "SAE J1453", "region": "American Connections", "thread_type": "straight thread", "seat_angle": "flat face", "seal_method": "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.", "id": "sae-j1453-orfs", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/sae-j1453-orfs/", "source": "https://brennaninc.com/connection-types/", "source_quote": "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.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "SAE J1926 Straight Thread O-Ring Boss (ORB)", "governing_standard": "SAE J1926", "region": "American Connections", "thread_type": "straight thread", "seat_angle": "flat surface", "seal_method": "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.", "id": "sae-j1926-straight-thread-o-ring-boss-orb", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/sae-j1926-straight-thread-o-ring-boss-orb/", "source": "https://brennaninc.com/connection-types/", "source_quote": "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.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "SAE J512 45\u00b0", "governing_standard": "SAE J512", "region": "American Connections", "thread_type": "straight thread", "seat_angle": "45\u00b0", "seal_method": "The male and female connections have 45\u00b0 seats, where the seal is make where the male flare and the female cone meet.", "interchangeability_notes": "dash sizes: -02, -03, -04, -05, -08, and -10 of SAE 37\u00b0 and SAE 45\u00b0 have the same threads, but NOT the same seat angles. Intermixing the two different types of fittings will result in leakage", "id": "sae-j512-45", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/sae-j512-45/", "source": "https://brennaninc.com/connection-types/", "source_quote": "SAE J512 45\u00b0 connections are used in automotive, refrigeration and truck pipe systems. These connectors are typically brass material. The male and female connections have 45\u00b0 seats, where the seal is make where the male flare and the female cone meet. This is a mechanical connection also.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle" ], "derived_fields": [ "region" ] }, { "connection_type": "SAE J512 Inverted", "governing_standard": "SAE J512", "region": "American Connections", "thread_type": "straight thread", "seat_angle": "45\u00b0 flare", "seal_method": "The male connector is either a 45\u00b0 flare within the tube fitting or a 42\u00b0 seat in the machined adapter. The female incorporates a straight thread with a 42\u00b0 inverted flare. The fittings are sealed at the flared surfaces.", "id": "sae-j512-inverted", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/sae-j512-inverted/", "source": "https://brennaninc.com/connection-types/", "source_quote": "SAE J512 inverted connections are typically used in automotive systems. The male connector is either a 45\u00b0 flare within the tube fitting or a 42\u00b0 seat in the machined adapter. The female incorporates a straight thread with a 42\u00b0 inverted flare. The fittings are sealed at the flared surfaces. These threads also maintain a mechanical connection.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle", "thread_type" ], "derived_fields": [ "region" ] }, { "connection_type": "SAE J514 JIC/37\u00b0", "governing_standard": "SAE J514", "region": "American Connections", "thread_type": "straight thread", "seat_angle": "37\u00b0", "seal_method": "Both male and female components have 37\u00b0 seats. The seal is made by establishing contact between the male flared and female coned seat.", "interchangeability_notes": "dash sizes: -02, -03, -04, -05, -08, and -10 of SAE 37\u00b0 and SAE 45\u00b0 have the same threads, but NOT the same seat angles. Intermixing the two different types of fittings will result in leakage", "id": "sae-j514-jic-37", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/sae-j514-jic-37/", "source": "https://brennaninc.com/connection-types/", "source_quote": "SAE J514 JIC/37\u00b0 hydraulic connections are common in most fluid power systems. Both male and female components have 37\u00b0 seats. The seal is made by establishing contact between the male flared and female coned seat. This is also considered a mechanical connection.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle" ], "derived_fields": [ "region" ] }, { "connection_type": "SAE J518 4-Bolt Flange", "governing_standard": "SAE J518", "region": "American Connections", "thread_type": "flange bolts", "seat_angle": "flat surface", "seal_method": "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.", "interchangeability_notes": "Excluding bolt sizes, SAE J518, JIS B 8363, ISO/DIS 6162 and DIN 20066 are interchangeable.", "id": "sae-j518-4-bolt-flange", "url": "https://referencesource.org/industrial-cross-reference-bearings-seals-fittings/sae-j518-4-bolt-flange/", "source": "https://brennaninc.com/connection-types/", "source_quote": "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.", "verified_fields": [ "connection_type", "governing_standard", "seal_method", "seat_angle" ], "derived_fields": [ "region" ] } ] }