AS B233 PDF

Screw thread measuring cylinders

AS B233 – Screw thread measuring cylinders

Provides a series of standard cylinders used for checking the effective (pitch) diameter of external threads, and covers standard ranges of ISO inch, ISO metric, Whitworth and BA threads. Two grades of measuring cylinder are covered, Grade A (pitch-line) and Grade B (grouped), the latter series being the same as the so-called ‘best size’ cylinders introduced by the National Physical Laboratory and amended and extended to cover ISO screw threads. Diameters of standard cylinders and P-values are given in inch and metric measures and some theoretical data, including relative merits of grades A and B, are also included.