Identification sheet
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.
10 rows1 sectionsLandscape
| Standard | Thread family | Flank angle | Parallel or tapered | Seat | Where 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 degrees | Parallel | 37 degree flare cone | Metal 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 degrees | Parallel | O-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 degrees | Parallel | O-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 degrees | Parallel | 45 degree flare cone | Metal 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 degrees | Tapered, 1 in 16 | Tapered thread, sealed on the thread | The 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 degrees | Parallel | Parallel thread, sealed on a face gasket | A bonded seal washer or O-ring at the face. The parallel thread cannot seal on itself. |
All 10 rows across 1 sections, black on white, column headers repeating at the top of every page, banded rows, no row split across a page break, landscape. Print it or save it as a PDF.
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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.
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Every value on this page was checked against 21 independent published sources: