The wall thickness of pipes - Gauge and decimal parts of an inch
Wall thickness of a pipe is normally given in decimal part of an inch rather than as fraction or gage number. When gauge numbers is given for a pipe without reference to a system, Birmingham Wire Gauge - BWG - is implied.
Birmingham Wire Gauge is also known as Stubs' Wire Gauge, used for drill rod and tool steel wire.
Gauge Birmingham Wire Gage
B.W.G.
(inches)
00000 (5/0) 0.500
0000 (4/0) 0.454
000 (3/0) 0.425
00 (2/0) 0.380
0 0.340
1 0.300
2 0.284
3 0.259
4 0.238
5 0.220
6 0.203
7 0.180
8 0.165
9 0.148
10 0.134
11 0.120
12 0.109
13 0.095
14 0.083
15 0.072
16 0.065
17 0.058
18 0.049
19 0.042
20 0.035
21 0.032
22 0.028
23 0.025
24 0.022
25 0.020
26 0.018
27 0.016
28 0.014
29 0.013
30 0.012
31 0.010
32 0.009
33 0.008
34 0.007
35 0.005
36 0.004
http://www.engineeringtoolbox.com/BWG-wire-gage-d_508.html