Drilling through firewall with step bit issue

That's how I drill every hole,

"for fuck sakes"

"jesus christ, really?"

"you mother fucking tit, JUST GO THROUGH ALREADY"

Especially when I'm working with stainless. PIA

 

Brake rotors

 

I don't think so, I haven't tried

 

Stainless sucks even with a grinder

 

Thanks all, from your comments I guess I must have gone too fast, pushed too hard, and heated it up, which caused the thin steel to flange out instead of getting cut.

I just got a new harbor freight step bit and will try again. I've been using tap oil.

If this doesn't work, I'll order a traditional 1-1/4" drill bit with a 1/2" shank.

 

Fixed that for you

 

Move the fiber back out of the way. That could be interfering with the drill bit cutting.

 

You can go fast at the start, but at 1.25" diameter you don't want to be over 250 rpm.

A new bit and and cutting as slow as you can should get you there. Slower is always better than faster here.

I have a harbor freight step drill and it has successfully put 6 holes of this approximate size in heavy gauge 18-8 stainless. Still looks new, too.

 

If 1.36" works, I'd use a Greenlee hydraulic knockout.

 

Got it done. The new step bit and going slow and cleaning the bit and re-lubing every 20 seconds or so with tapping fluid did it for me. Thanks for the tips!

It was nice to see that flange that had formed get cut off. I was able to just pull it out. The third picture shows where the cables will come into the cab.

 

That big ass hole for the grommet to reduce that much? Wtf

 

It's so you can cut and adjust it as you add more and more wires: