Monday, Jun 18, 2007 at 21:02
Hi again Bird, B&S stands for Brown & Sharp and was the cable gauging standard used before AWG ( American Wire Gauge ) was introduced.
Both B&S and AWG are the same size and are also simply known a s the cable Gauge or G, in other words, a cable could be marked in any of three Gauging type but be the same such as 6B&S, 6 AWG and 6G and the cable would be the same size ( 13.5mm2 ).
It may seem a bit confusing ( and it is ) but if you need to order cable, try to get it as B&S as this is a fairly commonly used size system or ask for the cable in square mm which is marked as above with the 6B&S, 13.5mm2. This mm2 is the cross sectional area of the actual copper in the cable.
To add to the confusion, here in Australia
( Britain ) there is also a cable sizing system marked with Auto or Automotive cable, for example, the cable mentioned above in your first post was referring to 6mm, which is a shortened way of stating 6mm Automotive cable.
Any cable with an Automotive size marked on it and no other cable size given, take care as the is no real defined size in this marking system as the Auto measurement is the total width of the cable including it’s plastic insulation.
Your 6mm is actually only somewhere about 4.5mm2, depending on what company made the cable.
Now your really confused and just to make it more confusing, when using the B&S sizing, the higher the number the thinner the wire. That makes sense doesn’t it, NOT.
Here is a basic list of commonly used sizes set out from thinnest to thickest and hopefully will help you pick cable sizes that you require.
4mm Auto = 1.85mm2 or there abouts
5mm Auto = 2.9mm2 or there abouts
6mm Auto = 4.58mm2 or there abouts
8B&S = 7.9mm2
6B&S = 13.5mm2
4B&S = 21.5mm2
2B&S = 33.6mm2
With the exception of the 10mm2 and the 16mm2, all these sizes may vary slightly from one cable brand to another.
Cheers and i hope this hasn’t muddied the water too much.