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Identification sheet

Seat and thread identification: all ten standards

The one-page decision sheet. Every standard the database covers with its thread form angle, whether the thread is parallel or tapered, what the sealing surface looks like, and where the joint actually seals.

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Seat and thread identification: all ten standards

10 rows. Print landscape.

Seat and thread identification: all ten standards. The one-page decision sheet. Every standard the database covers with its thread form angle, whether the thread is parallel or tapered, what the sealing surface looks like, and where the joint actually seals.
StandardThread familyFlank angleParallel or taperedSeatWhere it seals
Every standard, by what you can see and measure
JIC 37 degree flare (SAE J514 / ISO 8434-2)Unified inch (UN / UNF)60 degreesParallel37 degree flare coneMetal to metal, cone against the flared tube or the mating cone. No O-ring, no sealant.
O-ring face seal, ORFS (SAE J1453 / ISO 8434-3)Unified inch (UN / UNF)60 degreesParallelO-ring face seal (flat face)The O-ring squashed between the two flat faces. The thread only holds the load.
SAE straight thread O-ring boss, ORB (SAE J1926-1 / ISO 11926-1)Unified inch (UN / UNF)60 degreesParallelO-ring boss (straight thread port)The O-ring squashed between the fitting shoulder and the machined spotface of the port. The thread only holds the load.
SAE 45 degree flare (SAE J512 / SAE J533)Unified inch (UN / UNF)60 degreesParallel45 degree flare coneMetal to metal, cone against the flared tube. No O-ring, no sealant.
American National Pipe Taper, NPT (ASME B1.20.1) and NPTF dryseal (ASME B1.20.3)American pipe (NPT)60 degreesTapered, 1 in 16Tapered thread, sealed on the threadThe thread flanks wedging together, normally with a thread sealant or PTFE tape. The seal is the thread.
British Standard Pipe Parallel, BSPP or G (ISO 228-1)Whitworth (BSP)55 degreesParallelParallel thread, sealed on a face gasketA bonded seal washer or O-ring at the face. The parallel thread cannot seal on itself.
British Standard Pipe Taper, BSPT, R external and Rc internal (ISO 7-1)Whitworth (BSP)55 degreesTapered, 1 in 16Tapered thread, sealed on the threadThe thread flanks wedging together, normally with a thread sealant or PTFE tape. The seal is the thread.
Metric 24 degree cone, DIN 2353 / ISO 8434-1, light (L) and heavy (S) seriesISO metric60 degreesParallel24 degree cone (DIN)The 24 degree cone against a cutting ring bitten into the tube, or against a soft seal captured in the cone on the sealing-cone version.
JIS 30 degree flare on a BSPP thread (JIS B 0202 thread form)Whitworth (BSP)55 degreesParallel30 degree flare cone or seatMetal to metal, a 30 degree female seat against a 30 degree male cone.
Komatsu style 30 degree flare on a metric threadISO metric60 degreesParallel30 degree flare cone or seatMetal to metal, a 30 degree female seat against a 30 degree male cone.

Sources: ANSI/ASME B1.20.1, Pipe Threads, General Purpose (Inch), Table 1 (ASME); ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads, Table 1 (ISO); ISO 7-1, Pipe threads where pressure-tight joints are made on the threads, Table 1 (ISO); Hydraulic coupling identification chart E2/50101 (Gates); Fluid Ports and Connectors Identification Guide (McGill Hose & Coupling); Master catalogue: conformance, working pressure and torque tables (Tompkins Industries); Catalogue page 4: SAE J514 working pressure ratings, and SAE J1453 working, proof and minimum burst pressures for face seal fittings (Brennan Industries); Thread and connector identification guide (Gerrard Hydraulics (RYCO)); SAE threads reference tables (RYCO Hydraulics); How to identify British threads and fittings (Adaptall); How to identify 24 degree tube fittings, component compatibility chart (Adaptall); Thread identification: BSP, JIC, ORFS and metric tables (Apex Fluid Power); Thread identification guide, O-ring face seal, with adapter sizing chart (Central Hydraulic Supply); High pressure pipe connectors: DIN 2353 working pressure table (Tubes International); Boss, face and flange O-rings: AS568 900 series and zero series (Global O-Ring and Seal); JIC fitting thread sizes (GageRef); ORFS fitting thread sizes (GageRef); NPT thread chart (AmesWeb); BSPP thread chart and calculator (AmesWeb); NPT thread charts (Machining Doctor); BSP thread charts, BSPP and BSPT (Machining Doctor).

Reference aid for identification and ordering, not a substitute for the manufacturer specification. Pressure ratings apply only under the conditions printed beside them. Verify against the maker's catalogue before a system is charged.

Free to read

Every figure on this sheet, on its own page

Nothing on this sheet is behind the paywall as information. Each standard below has a free index carrying the same table, and each size has its own page with the measured span, the seat, what it mates with and the sources behind every figure.

JIC 37 degree flare13 sizes, freeSAE J514, ISO 8434-2ORFS (O-ring face seal)8 sizes, freeSAE J1453, ISO 8434-3SAE O-ring boss13 sizes, freeSAE J1926-1, ISO 11926-1SAE 45 degree flare8 sizes, freeSAE J512, SAE J533NPT / NPTF10 sizes, freeASME B1.20.1, ASME B1.20.3BSPP (G)12 sizes, freeISO 228-1, BS 2779BSPT (R)10 sizes, freeISO 7-1, BS 21Metric DIN 24 degree20 sizes, freeISO 8434-1, DIN 2353JIS 30 degree flare (BSPP)9 sizes, freeJIS B 0202, ISO 228-1Komatsu 30 degree flare (metric)7 sizes, freeISO 261, manufacturer catalogue dimensions

More sheets

Other identification charts

SAE inch fittings: JIC 37, ORB, ORFS and SAE 4542 rowsPipe threads: NPT, BSPP and BSPT32 rowsMetric DIN 2353 / ISO 8434-1, light and heavy series20 rowsJapanese fittings: JIS 30 degree and Komatsu 30 degree16 rowsPublished working pressures, with the conditions they apply under61 rows

Where these figures come from

Every value on this page was checked against 21 independent published sources: