Sandvik Coromant Threading - Manual (Page 8)

8
A
B
BSW
BSF
BSP. F
ISO 228/1 G
1 ½
ISO 7/1 = R
p
1 ½ R
p
7/1 = R
c
1 ½ R
c
7/1 = R 1 ½ R
1. Basic in threads
Whitworth pipe threads:
Tolerance position
Fine Only
one
class
Coarse
Whitworth threads (G, R, BSW, BSF, BSPF)
Whitworth screw threads are now obsolete, but Whitworth pipe
threads are a recognized international standard. There are two
tolerance classes for external-, and one tolerance class for internal
Whitworth pipe threads.
Whitworth pipe thread designations
These threads are divided into 2 groups:
• Pressure-tight joints not made on the thread, ISO 228/1
• Pressure-tight joints made on the thread, ISO 7/1
Examples of Whitworth pipe thread designations:
Pressure tight joints not made on the thread:
= G 1 ½ A
(external)
= parallel thread
= G 1 ½ (internal) = pipe diameter, not thread diameter
A or B = external tolerance class only
Pressure tight joints made on the thread:
= parallel thread, internal
= conical thread, internal
= conical thread, external
Sandvik Coromant’s WH inserts are to be used for parallel threads.
The PT inserts are for the conical thread.