BSPT is an obsolete screw thread designation which is still in
common usage. It has been replaced with the R-Series designations.
What was BSPT screw thread is now R-Series screw thread with no
major physical differences.
The screw thread is defined in at least three places: BS-21 and ISO-7 and EN-10226.
These three screw thread standards, as they relate to the product
screw threads are technically equivalent.
The R-Series of threads includes:
R = external tapered thread for fits made on the thread per ISO-7/1 & BS-21 & EN-10226/1 & EN-10226/2.
Rc = internal tapered threads for fits made on the thread per ISO-7/1 & BS-21 & EN-10226/2.
Rp = internal parallel thread for fits made on the thread per ISO-7/1 & BS-21 & EN-10226/1.
Rs = external parallel thread for fits made on machined face per
BS-21 Appendix C.
EN-10226/3 and ISO-7/2 agree on the gage designs. The screw thread gages defined in BS-21 are different from those in ISO-7/2 & EN-10226/3.
The differences are for the most part minor and will only result
in variation between types at the edge of the product tolerances.
DISCLAIMER
As always, obtain approval or consensus from your customer. This
data is provided for general information only. The intention is
to provide accurate information; regardless; errors may exist in
the supplied information. If accuracy is critical, base your final
decisions on the data provided in the root documents: ISO-7 or BS-21 or EN-10226 which are copyrighted document. To purchase a copy
visit an Authorized Reseller.
COMMENTS
Original Posting: 10/17/2008
Last Revision: 8/7/2014
Error corrections in, or comments about, the above data can be sent
to: office@gagecrib.com.
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