Nail and screw detector?

Impossible? perhaps if you explain in a bit of detail as to why you want to find nails/screws someone could come up with an idea?

-- Sir Benjamin Middlethwaite

Just use some strong neodymium magnets (I used 4 off 1/2" x 1/8" from Ebay or

Brilliant tip. Cheers

Yes - brilliant!

I need to fix shelf brackets to the wooden studs underneath, but had forgotten to mark the centres on the floor before the plasterers came. However, I do know that the studs are accurately vertical, and the plasterboard screws are accurately on the centre-lines.

All right then... old pair of headphones... crunch... small ceramic magnet... scan delicately across wall... magnet sticks to wall over screw head, exactly as advertised... mark... scan up and down... mark... mark... good vertical line. Next stud, etc.

Excellent - thanks, Ian!

Oh you might want to wrap insulation tape round magnets as:-

1. The nickel coating leaves marks on emulsion paint (not a problem if removing).
2. The magnets are prone to shattering if they say "jump" to something ie screwdriver used to remove screws.

Thanks for the warnings. The magnets I used weren't prone to either of those problems (probably because they were nowhere near as strong as the ones you used) but it's best not to find out the hard way.