drilling into frame for sliders

I searched and read a lot on drilling into the frame however I think it led to more questions than answers..

• Threads stated use 1/4 in then jump to 9/16 to finish. others state stage from 3/16-1/4-3/8-9/16. Which way is best?

• Lubricating oils... grease or spray? wd-40 or something different?

• With others who have drilled through frame.. what would you do the same or different if had to do it again? how many bits did you go through?

the truck you guys are helping out

 

step your drill bits.........once you get past 5/16' slow the drill speed down.if you have a cordless drill that has a 2 speed use the lower speed. cutting oil will help aswell.

 

I used a screw machine drill bit (short and stubby) with titanium nitride coating. For drilling on the bottom frame flange, I used my Subaru's scissor jack to apply pressure. Used a lot of motor oil as cutting fluid.

If I had to do it over again, I'd use stepped drill bits like these:

 

I used 1 giant ass drill bit, a right angled drill, a floor jack to make redneck inverted drill press, and plenty of cutting oil