In the description it says "form jaws bend pipes without deformation". I haven't done any wiring for the car yet, but I've tested these pliers on a bunch of broken wires and you can use them to snag and twist the wire if you're not careful. The first few corners were ok and then I had a kink. so they are not reliable. What works well for fairly tight 90 degree bends and costs about the same as these pliers is the titanium mini tube bender, which you can also find here at Revain. I bought one of these at the same time and played with it and it worked great.