
29. Basic profile of threads
■Metric Screw Threads ■Unified Screw Threads
Production data
Internal Internal
Thread Thread
External External
Thread Thread
d1 or D1
d2 or D2
d1 or D1
d2 or D2
d or D
d or D
Threads per inch
■Whitworth Screw Threads ■Screw Threads for Sewing Machine
Internal Internal
Thread Thread
External External
Thread
d1 or D1
d2 or D2
d1 or D1
d2 or D2
Thread
d or D
d or D
D1’
D1’
Threads per inch Threads per inch
■Miniature Screw Threads ■Parallel Pipe Threads
Internal
Internal Thread
Thread
External External
Thread Thread
d1 or D1
d2 or D2
d1 or D1
d2 or D2
d or D
d or D
Note : This figure rounds off 0.320744H.
Threads per inch
■Taper Pipe Threads ■Taper Pipe Threads (Parallel)
Internal
Thread
Internal
Thread
read
External Th
Information
Technical
Central axis line of thread Central axis line of thread
Threads per inch Threads per inch
Technical-82
853