How do you guys cut large holes into thick steel?
And how/when do you swage them?


I need to cut a large oval hole in some 3mm steel for my adjustable top mounts.
How do you guys do it at home?
I could use a hole saw and cut 2 holes (in this case each hole would be 40mm making say 65mm in length) overlapping other but that's a bit tricky and my hole saw might not like it too much as I would need to drill 4 holes.

Next question,
When do you need to swage a hole? And what for? Does it add strength?
How do you do it? Use a press and push a socket that's slightly too big through it? In my case 45mm?

Thanks