Paul McGowan:
When it comes to wire sizes, numbers are confusing. Take for example our power cords. Our lowest cost power cable is based on 12 gauge wire, the next up 10 gauge, then 8. And from these numbers you’d imagine the size of each power cord is getting smaller, corresponding to the smaller number, yet you would be wrong. 8 gauge wire is considerably thicker than 12, and 2 gauge wire is huge, while 30 gauge wire is as thin as hair. Why do the gauge sizes not match the numbers? Surely a higher number should describe a thicker wire. Right?
The answer to this puzzle is interesting. The number does not describe the size of the wire, but the number of process needed to get it there.
Wire starts out as a block of copper, which is pulled through a small opening called a die. This pulling process is called drawing, and it is the opposite of how toothpaste gets on your brush, or pasta comes out of a machine. Toothpaste and pasta are extruded, or pushed through a die. Wire is pulled, or drawn through a die. And you can only change copper’s shape so much before it breaks. The first pull of wire is 0 gauge and that’s really thick wire. To make it thinner, we start with 0 gauge and pull it through a smaller opening and we get One gauge, and so forth.
You can see that by the time we get to twenty gauge, or even 30 gauge, the copper has been pulled and pulled time and again to get that thin.
So the next time you’re at the nerd cocktail party and the inevitable question of wire gauge comes up, you will be in the know!