Australian Pipe Threads of Whitworth Form

Australian pipe threads are divided into two distinct groups, sealing pipe threads and fastening pipe threads.

SEALING PIPE THREADS - Designated "R" to AS 1722 Part 1 (Formerly BSPT) are based on ISO 7/1 where pressure tight joints ARE made on the mating threads. These threads are intended for Pipes suitable for screwing and for cocks, valves and other fittings to be connected to screwed Pipes. If necessary an appropriate jointing medium may be used on the threads to ensure pressure tight joints. The male thread "R" is always tapered (1:16 included). The internal thread may be parallel "RP" or tapered (1:16 included) "RC". (See figure 1)

FASTENING PIPE THREADS - Designated "G" to AS 1722 Part 2 (Formerly BSPF) are based on ISO 228/1, where pressure type joints are NOT made on the threads. These threads are intended for the mechanical assembly of the component parts of fittings, cocks, valves, accessories etc. If these assemblies must be pressure tight this will be achieved by compressing two surfaces other than the thread and the use of jointing medium if necessary e.g. gaskets on flanges or '0' rings. 

Both male and female threads are always parallel.

For internal threads one class of tolerance is provided "G".
For external threads two classes of tolerance on the pitch diameter are provided, class "GB" is used for general applications and will be supplied where no tolerance class is stated ."GA" tolerance class is half that of "GB" and is used for special applications. (See figure 2)

<Back

S.G. Prittie Precision Gauges Pty. Ltd. ABN 23 004 719 733 21 King Street Airport West Victoria 3042 Australia Telephone (613) 9335 5200 Facsimile (613) 9335 5201 E-mail sales@prittie.com.au

Copyright © 1999-2003 S.G. Prittie Precision Gauges Pty. Ltd. All rights reserved.