II
S O M T A P 1 2 C A T A L O G U E
Threads
Tolerance
Direction of
Cut
Taper, Through
& Blind Hole
Through &
Blind Hole
Blind Hole Tapping
Through Hole Tapping
Left Hand
Cutting
Right Hand
Cutting
Hand Taps
Metric
Metric Fine
British Standard
Whitworth
British Standard
Whitworth
Fine
Unified National
Coarse
Unified National
Fine
British Standard Pipe
Taper “F” Series
British Standard Pipe
(Fine) “G” Series
National Pipe
Straight
National Pipe
Taper
British
Association
Thread Form - with
47½°/55°/60° flank
angle
Woodruff
Tolerance
Corner Rounding
Tolerance
BSP
BSB
NPS
MF
M
BSW
BSF
UNC
UNF
BSPT
NPT
BA
British Standard
Brass
Tolerance on
cutting Diameter
Application
GENERAL
MATERIAL DESCRIPTIONS
Code 0
Code 1
Code 2
Code 3
Code 4
Code 5
Code 7
Free Cutting Steels
Carbon Steel
Alloy Steel
Stainless Steel
Heat Resisting Alloys
NimonicAlloys
Titanium
Tool Steel
Cast Irons
Nickel
Manganese Steels
AluminiumAlloys
MagnesiumAlloys
ZincAlloys
Copper
Synthetics / Plastics
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Materials
ICON
LEGEND & DESCRIPTION
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