BS EN ISO 228-1: 2003 Table 1 Thread dimensions …

1 BS EN ISO 228-1: 2003 Table 1 Thread dimensions british pipe Thread ( whitworth Form) -- Parallel (BSPP/BSPF) -- (G). Tolerance on minor Tolerance on major Tolerances on pitch diametera diameter diameter Diameters Internal Thread TD2 External Thread Td2 Internal Thread TD1 External Thread Td Number Desig- of nation threads Lower Lower of in Pitch Height of major d pitch d2 minor d1 Lower Upper deviation deviation Upper Lower Upper Lower Upper Thread mm P Thread h =D = D2 = D1 deviation deviation Class A Class B deviation deviation deviation deviation deviation 1/16 28 0 0 0 0.

2 1/8 28 0 0 0 0. 1/4 19 0 0 0 0. 3/8 19 0 0 0 0. 1/2 14 0 0 0 0. 5/8 14 0 0 0 0. 3/4 14 0 0 0 0. 7/8 14 0 0 0 0. 1 11 0 0 0 0. 1 1/8 11 0 0 0 0. 1 1/4 11 0 0 0 0. 1 1/2 11 0 0 0 0. 1 3/4 11 0 0 0 0. 2 11 0 0 0 0. 2 1/4 11 0 0 0 0. 2 1/2 11 0 0 0 0. 2 3/4 11 0 0 0 0. 3 11 0 0 0 0. 3 1/2 11 0 0 0 0. 4 11 0 0 0 0. 4 1/2 11 0 0 0 0. 5 11 0 0 0 0. 5 1/2 11 0 0 0 0. 6 11 0 0 0 0. Note: Class B applies only to external threads. Internal threads are Class A. BS EN ISO 228-1: 2003 data chart above revised and updated 12/20/11. These standard pipe threads are formally referred to by the following sequence of blocks: the words " pipe Thread ", the document number of the standard ( , "ISO 7" or "EN 10226").

3 The symbol for the pipe Thread type: o G = external + internal parallel (ISO 228). o R = external taper (ISO 7). o Rp = internal parallel (ISO 7/1). o Rc = internal taper (ISO 7). o Rs = external parallel the Thread size Threads are normally right-hand. For left-hand threads, the letters "LH" are appended. Example: pipe Thread EN 10226 Rp 2 . The terminology for the use of G and R originated from Germany (G for gas, as it was originally designed for use on gas pipes; R for rohr (meaning pipe ).).