Rounded 7mm hex

[arsenaljordan]

Trying to change the discs and pads on a Vauxhall Calibra that's been neglected. The lower slider bolt on drivers side is rounded, my 7mm hex bit has nothing to bite to so can't get it undone.

Read a couple of posts here, but they're full of conflicting information. The bolt is counter sunk down into a rubber grommet, so wouldn't be able to weld something to it even if I had a welder so that's not an option. Ofher options are to use an extractor to force it out or to hammer a torx bit into it.

Am I right in thinking the easiest option will be to hammer a T45 torx in?

Any help greatly appreciated!

[E-bmw]

Don't know if the t45 is the right one, but just hammer in whatever size is too big to fit straight in, make sure it is fully home & well held in place.

[urquattroGus]

Hammer a Torx in or a 8mm allen head, then maybe shock the end of what you are turning it with a hammer (carefully!)

[PositronicRay]

I'd hammer the torx bit in then use an impact screwdriver on it.