Cutting D-shaped and double flat holes

I didn't see any sub-forums on fabrication so I will ask here.

How do you go about cutting the D-shaped and double flat holes in your home shops? The dremel tool method is getting old fast (faster than I can cut them LOL).

A nibbler. An expensive D punch for D shaped connectors. A BNC D punch wasnt too bad price wise.

A CNC router.

Layout and file for one or two holes You drill the biggest hole that will fit inside the opening first then file to fit. Don't use a twist drill get a step drill, they will save a lot of cussing.
Step drills -

If you do a lot of holes buy the correct Greenlee punch and die. https://www.greenlee.com/us/en/search?BaseQuery=D+punch

If you go with the greenly dies, invest in an cordless impact driver (I have the Milwaukee 18v brushless) Pops a perfect d-shaped hole.

gophert never thought about that. I do own a manual impact tool somewhere that you hit with a hammer. I do have a 20 ft-lb Bosch demolition hammer, but not a hammer drill - yet.

gophert said:

If you go with the greenly dies, invest in an cordless impact driver (I have the Milwaukee 18v brushless) Pops a perfect d-shaped hole.

Click to expand...

Thank you for the wonderful advice, I regularly punch 24mm and 22mm round holes at work, and find it hard work with just an adjustable spanner.

So following your suggestion, I ordered a De Walt cordless impact driver (a brushed one, as it's cheaper, and it's not going to get a lot of use), and a De Walt one because we already have a couple of De Walt cordless tools, and this means all three use the same batteries. I ordered it complete with case, charger, and two batteries as it was only £30 dearer than the bare tool, and you can't have too many batteries.

Anyway, it's arrived, I got some adaptors and a suitable socket - just tried it, and it's absolutely incredible. Takes a couple of seconds, and no effort required at all.

So anyone else using manual hole punches, take gophert's advice and buy a cordless impact driver.