I'm attaching to the frame. The frame is probably 10ga, so about 1/8" thick metal. 1) I can drill a hole, install a rivnut and attach cable. 2) I can use a self tapping bolt into the appropriate sized drilled hole. 3) I can get a nut behind to the inside of the frame and sandwich a bolt thru the cable, frame and tighten to nut. The rivnut may be in a bad place to reach with a manual setter, but which of the other two is better for grounding the frame?
I use the OEM style "self tappers" they have a finer pitch than the "self tappers" on the market. (and why those old coffee cans full of 60+ year old hardware is worth it's weight in real copper pennies) If the strap does not have serrated terminal, use a serrated washer between the terminal and the frame.
