## Thursday 23 January 2014

### SWG what does this mean?

I needed a quote for a British car part being manufactured, the drawing I have is marked as
using 16swg steel plate.

SWG
n
1. (Metallurgy) Standard Wire Gauge; a notation for the diameters of metal rods or thickness of metal sheet ranging from 16 mm to 0.02 mm or from 0.5 inch to 0.001 inch

In real terms, well in Metric this is around 1.6mm thick.

The Sunbeam Imp Sport oil cooler mounts are the parts being remade.

My digital micrometer gave me a reading around 1.68mm thick, the paint makes for the extra thickness?

Always learning?

Roy

# Standard wire gauge

A standard wire gauge.
British Standard Wire Gauge is a set of wire sizes given by BS 3737:1964 (now withdrawn), and is generally abbreviated to SWG. It is also known as: Imperial Wire Gauge or British Standard Gauge. Use of SWG sizes has fallen greatly in popularity, but is still used as a measure of thickness in guitar strings and some electrical wire. Cross sectional area in square millimetres is now a more popular size measurement. The current British Standard for metallic materials such as wire and sheet is BS 6722:1986, which is a solely metric standard.
SWG was fixed by Order of Council August 23, 1883. It was constructed by improving the Birmingham Wire Gauge. It was made legal standard March 1, 1884 by the British Board of Trade.
The basis of the system is the mil, or 0.001 in. No. 7/0, the largest size, is 0.50 in. (500 mils or 12.7 mm) in diameter, and the smallest, No. 50, is 0.001 in. (1 mil or about 25 µm) in diameter. Between each gauge, the weight diminishes by approximately 20%. Because the weight per unit length is related to the area, and therefore the square of the diameter, the diameter diminishes by approximately 10.6%:
$\mbox{Diameter Ratio} = 1-(1-0.2)^{\frac{1}{2}} \approx 10.6%$

A table of wire gauges and diameters is shown below.[1][2] The relationship of diameter to gauge is piecewise linear, only approximating a (constant-ratio) exponential curve.
British SWG (Standard Wire Gauge) diameters
SWGinmmstep
7/00.50012.7000.036"/gauge
6/00.46411.7860.032"/gauge
5/00.43210.973
4/00.40010.1600.028"/gauge
3/00.3729.4490.024"/gauge
2/00.3488.839
00.3248.230
10.3007.620
20.2767.010
30.2526.4010.020"/gauge
40.2325.893
50.2125.385
60.1924.8770.016"/gauge
70.1764.470
80.1604.064
90.1443.658
100.1283.2510.012"/gauge
110.1162.946
120.1042.642
130.0922.337
140.0802.0320.008"/gauge
150.0721.829
160.0641.626
170.0561.422
180.0481.219
190.0401.0160.004"/gauge
200.0360.914
210.0320.813
220.0280.711
230.0240.6100.002"/gauge
240.0220.559
250.0200.5080
260.0180.45720.0016"/gauge
270.01640.4166
280.01480.37590.0012"/gauge
290.01360.3454
300.01240.31500.0008"/gauge
310.01160.2946
320.01080.2743
330.01000.2540
340.00920.2337
350.00840.2134
360.00760.1930
370.00680.1727
380.00600.1524
390.00520.13210.0004"/gauge
400.00480.1219
410.00440.1118
420.0040.1016
430.00360.0914
440.00320.0813
450.00280.0711
460.00240.0610
470.00200.0508
480.00160.0406
490.00120.03050.0002"/gauge
500.00100.0254