Die grinders.

[afstruct]

I know the drill bits you're discussing, I've used them in a Desoutter right angle pneumatic drill. Pain in the butt.
Also used a really weird little tool that that looked sort of like a box ratchet, with a 1/4" shank at one end (attached to an air drill) and the other end had a threaded recess for screwing in a special L/H 1/4" drill bit about 20mm long. The drill bit pointed back towards the user.
The 'box ratchet' was about 100mm long and had a gear train inside, why it required a L/H drill.
It was used to remove the remnants of a broken spigot of a Delrin bumper pad on the backside of a B737 cargo door handle.

@afstruct does this relate to airframe structures?

Yeah , used those ( but for the life of me can't remember what we called them ).
Yeah we had a couple of different length ones that went in a normal drill.
Also ones that could only be used with their own special pneumatic drill. Had a few of these drills with different length drive shafts and different length box ratchet part.

Haven't done much work on B737s but definitely sounds like something we'd do .
I've found that in the commercial aviation world virtually all mechs and LAMEs don't want to know anything about metal work/composite work and repairs .
Why there's a TAFE cert 4 course ( is a trade ) for AME engineer Structures.
When I started it was really only metalwork. My original trade papers say Aircraft Sheetmetal Worker 1st class.

But now as structures you're qualified for composite work and able to do a lot of the mech work as well but at most places you're usually so busy with metal and composite work.

 

[lmoengnr]

Yeah , used those ( but for the life of me can't remember what we called them ).
Yeah we had a couple of different length ones that went in a normal drill.
Also ones that could only be used with their own special pneumatic drill. Had a few of these drills with different length drive shafts and different length box ratchet part.

Haven't done much work on B737s but definitely sounds like something we'd do .
I've found that in the commercial aviation world virtually all mechs and LAMEs don't want to know anything about metal work/composite work and repairs .
Why there's a TAFE cert 4 course ( is a trade ) for AME engineer Structures.
When I started it was really only metalwork. My original trade papers say Aircraft Sheetmetal Worker 1st class.

But now as structures you're qualified for composite work and able to do a lot of the mech work as well but at most places you're usually so busy with metal and composite work.

My original trade was Aircraft Mechanic-Engine. Retired as a LAME.
Had a few stints as a Project/Certifying Engineer supervising groups of sheeties and composite specialists carrying out structural repairs to airframes and flight controls. Learned heaps from the sheeties, they were all 'craftsmen'. They knew more about structural repairs than the specialist Boeing engineers....