drilling a hole in sheet metal

[AW10]

I need to drill a 40mm hole in the sheet metal of my car behind the bumper to install the towbar wiring. Can I use a hole saw like http://www.screwfix.com/p/erbauer-bi-metal-holesaw... on body sheet metal?

[Getragdogleg]

Yes, slowly with lube.

I had to do a 70mm hole in the back of a truck (to mount a reversing camera) and I used one of these even though the girder was 10mm thick. it took ages but worked fine.

[harrisp]

Holesaw will do the trick easily (i do similar daily) id pilot drill for the centre drill first.

[AW10]

Thanks chaps- was going to pour a bit of oil into an old can and dip the hole saw into it every 15 seconds or so to act as a lubricant and to cool the saw. It has an arbor which will ensure that the hole is drilled in the right place and that the hole saw doesn't wander.

[phillpot]

Drill the pilot hole without the hole saw on the mandrel, that way if it breaks through unexpectedly the hole saw won't "snatch" and make a mess.

[bimsb6]

Cone drill will do nicer job !

[AW10]

No worries - hole saw worked v well and a bit of work with a file to clean off the burrs and job done. Thanks for the tips.