Drill size?

Thank you for the link sir. Looks more complicated than I thought. But that is the best way to remove body panels without damage I believe. Thanks again everyone. Anyone know the size for the firewall?


Harbor Freight sells the same thing that Ron posted for a LOT less! Around $5 bucks I think.

There is more than 1 kind of spot weld cutter. The one shown is ok if the side of the part your drilling into is the part you'll be throwing out. If not, your going to a have a 3/8" hole to fill. That's a bit more than desired to weld up sometimes. (especially if it goes beyond the new part)

I use a combination of that type spot weld cutter and a regular 1/4 inch drill bit to go part way thru. Sometimes that's all you need. Carbide would be the ultimate if you go that way.


Well Known Member
I'm a machinist so I have access to some carbide drills. I want to have the correct tools that will last long enough to get the job done without trips to get more tools when they wear out. Guess I wll check out harbor freight too. Thank you for the suggestions.


Well Known Member
That makes sense, high surface footage kills tool steel on tougher parts. What speed do you use, 200 rpm or so? Do you use any cutting oil? That s what I have thot to use. Thank you for the tip sir. Seems like the spot welds go on forever on some places on these cars.


Well Known Member
thank you Mr black 63, that also makes sense. I have a #3 carbide center drill, pilot is .125, body .3125 I may use for this application. Thanks again for all this information from all the wonderful people on this site.