Cutting A Square Hole

[dobboy 231 2 Cars]

I've notice one of the fixings on the car for my drivers seat is suspect, the metal is kind of ripped.

 

(I could cut the same small section out a 205 and make it fit, and rivet it in to avoid having to get a welder round, but don't have a battery grinder to take to scrappies, but could cut it out with a reciprocator saw.)

 

If I wanted to fab it myself, anyone know the best way to make a square hole (about 20mm) on a bit of sheet metal? It has to be pretty accurate size to hold an 8mm captive nut?

[Biggles 65]

Drill an 18mm hole and then file it to square the size you need with a square file.

[acox99 74 1 Cars]

If you are repairing a seat mount do not rivet it, if you are involved in an accident that will fail and could result in servere injuries for yourself or passengers. Put it back as it should be. If it's welded then weld it again. Safety is more important than the hastle of finding someone to weld it.

[Slo 283 1 Cars]

You can't rivet a seat mount if the mount has cracked the steel around it what do you think it will do to rivets?

[dobboy 231 2 Cars]

Thanks ...... i have a solution.

 

It doesnt look like any of you are aware that the front of the seat is held in by speednuts!

[Slo 283 1 Cars]

Whats a speed nut and where do you mean?

[farmer 328 1 Cars]

Speed nut is a captive thread.

[Slo 283 1 Cars]

With a quick google I see what speed nuts are, but I dont see a problem with them? After all when you bolt it up it clamp against the surface it clipped too.