How to drill for a self-tapping metal screw for ground wire?

[kayakrguy]

Folks,

I need to attach my electrical ground to my trailer frame. I know the hitch has a self-tapping screw for the car wire ground for the running and brake lights. I am mounting electrical in the rear and would rather not have to rub ground wire all the way to the front. But, I have never drilled for self tapping screws...does it require a special drill bit?

Help appreciated!

Thanks,

Jim

[halfdome, Danny]

Generally a self tapping screw doesn't need a predrilled hole. For example when putting together aluminum gutters and down spouts. Since you are screwing into steel you'll need to use a high speed drill bit (common drill bit) and size the drill bit to the size of the shank of the screw not counting the screw threads, I would size it a smidgen larger too. I would scrape or better yet grind off any paint and use a large head screw for best contact for your ground. Danny

[kayakrguy]

Thanks, Dan

Jim