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Repost: The most comprehensive table of British thread specifications – worth saving. https://i1.go2yd.com/image.php?url=0L4ED2Ihkk* V; |$ f: W4 c+ G, ?4 ] " F3 o; }% G) T Q: A! b! D3 v" W. j https://i1.go2yd.com/image.php?url=0L4ED2ZQQg: J6 m1 F7 k: M’ j+ t/ d6 G * j9 i ]3 g3 t5 N1 b. |0 @ The RC2 inch tapered pipe thread has 11 threads per inch; the pitch is 25.4/11, which equals 2.309. The thread height (depth) is 2.309×0.64, resulting in 1.479. The taper ratio is fixed at 1:16. R is equal to 1/32 multiplied by the length – 1/32 means that the taper ratio of the threaded connection is 1:16, with a one-sided ratio of 1:32. The length refers to the positioning point plus the effective length; for example, if the positioning value is 3.0 and the effective length is 12.0, then R = 1/32 × (3 + 12) = 0.46875. https://i1.go2yd.com/image.php?url=0L4ED20KLD * G’ I$ A% M6 e3 W( X https://i1.go2yd.com/image.php?url=0L4ED2jEfE ‘ n( u4 @! _% b7 l2 Click to get free access to 10GB of tutorials on CNC turning/milling, UG programming, CAD drawing, CNC simulation, and books related to CNC machinery. https://i1.go2yd.com/image.php?url=0L4ED2ENxP& h” ?2 k* C1 ]9 y9 _ “ U- _! M” }# K! ]+ f2 n$ P4 n8 s https://i1.go2yd.com/image.php?url=0L4ED2xlTB * {( U& n4 ~9 t/ O/ ~/ U9 c https://i1.go2yd.com/image.php?url=0L4ED2PYEU 1. Sealed pipe threads (R): Basic dimensions and tolerance standards for British sealed pipe threads. There are two types of tolerances for British sealed pipe threads: a “cylindrical/conical” fit, which consists of a cylindrical internal thread and a conical external thread； Tapered internal threads and tapered external threads form a “taper/taper” fit. In Europe, “shank/taper” fit threads are primarily used ； Outside of Europe, **“posts/cones” in combination with threads are primarily used; the inspection standards for these two types of threads differ to some extent** ； The current ISO standard for sealed pipe threads in imperial units (ISO 7-2:2000) is based on a \"column/cone\" fit system. The complete designation for sealed pipe threads in imperial units consists of a thread characteristic code, a thread size code, and a rotation direction code. The characteristic code for sealed circular internal threads in imperial units is: RP ； The characteristic code for imperial sealed tapered internal threads is: RC ； The characteristic code for British standard sealed tapered external threads is: R1 (used in combination with British standard sealed cylindrical internal threads) ； R2 (used in conjunction with British sealing tapered internal threads) ； The rotation direction code for left-handed threads is LH ； The direction code for right-hand threads is omitted. For sealed pipe threads, RP/R1 and RC/R2 are used to denote \"shaft/taper\" and \"taper/taper\" thread pairs, respectively. 2. Unsealed pipe threads: The basic dimensions and allowable tolerances for imperial unsealed pipe threads are indicated as follows; the complete designation for an imperial unsealed pipe thread consists of a thread characteristic code, a thread size code, a pitch diameter tolerance class code, and a direction code. The characteristic code for imperial unsealed cylindrical threads is G. For imperial unsealed internal cylindrical threads, the pitch diameter tolerance class code is omitted ； The metric grade codes for the major diameter of British standard unsealed external cylindrical threads are A and B, while the direction code for left-handed threads is LH ； When indicating a pair of threaded connections using imperial unscrewed pipe threads, the direction code for right-hand threads is omitted; only the code for the external thread is specified. Examples: Right-hand, unscrewed circular internal thread with size code 2: G2. Right-hand, unscrewed circular external thread of grade A with size code 3: G3A. Left-hand, unscrewed circular external thread of grade B with size code 4: G4B-LH. A threaded connection consisting of a right-hand, unscrewed circular internal thread with size code 2 and a circular external thread of grade A: G2A. Pipe thread taps are used to cut internal threaded holes, while die sets are used to cut external threads. Others: Conversion of 55° tapered pipe threads. 55° tapered pipe threads refer to threads with a thread pitch angle of 55° and a taper ratio of 1:16. This series of threads is widely used around the world, and its designation varies depending on the country. China, the UK, France, and Japan use the ISO codes ZG, R (external), G, PT, RR (external thread); Rc (internal). Conical pipe threads with a 60° pitch angle are those whose thread angle is 60° and whose thread taper is 1:16. This series of threads is used in China’s machine tool industry as well as in the United States and the former Soviet Union. Its code was designated as K in our country in the past, then as Z, and is now changed to NPT.