I didn't know you could buy 12.5ga mild steel in coils. It must be for Chain Link?
Mild steel or low carbon wire isn't much compared to high tensile. It has a much lower breaking strength, and is usually either class 1 or commercial galvanized. It would make a subpar electric wire.
If it was me, I would take it back and get name brand 180 or 200KPSI high tensile wire. Also, pay more and get layer wound instead of coil wound. It unrolls so much better.
The prob is its not even 170, is not hi tensile. I thought maybe for electric top lines.
I like the 170 and 180. The 200 snaps everytime I try to tie a knot. When my brace wire fails, which isnt very often it is usually where the wire gets knicked from the teeth of something, or a fence is over stretched.
The scrap bin is the best use for it. I would never use 170 KPSI. That stuff is so soft and breaks so easy. We tried to build braces with 180kpsi wire before and every one would blow apart. Use 200kpsi minimum, 210 if you can find it. I would take it back.