15 replies to this topic

[dklawson]

20-30 strands is more like household mains wiring than what you want in a car for something that flexes. 20-30 strands for an earth cable in the boot is probably OK but it is not what you want for something that flexes or is subject to vibration.

For example, see the welding cable information table in the link below.
http://www.mcmaster....g-cable/=ggp5gr
Scroll down to the second table (the first table with part numbers and prices) and look at the entry for #2 cable.
Note that #2 weld cable is listed as having 624 strands. That is why the cable can flex more without failure and why the copper core diameter measures closer to 5/16" than the 1/4" that you measured on your cable.

Now scroll to the third table on the page for the heavy duty weld cables (Mine Safety Rated - MSHA)
Note that those cables have much thicker jackets and still finer stranding (1650 strands for #2). However, MSHA rated cable is impractical in most automotive applications because its jacket thickness is huge.

At the bottom of the page are "battery cables". Note that there they tell you the amp rating of the cable and the jacket diameter but not the stranding. However, you will also note that they describe the battery cables as "high flex" and mention that they are sometimes called welding cable. You can infer from those descriptions that the battery cables have fine stranding like the welding cables carrying the same size description and similar jacket diameter.