Plywood and screws...

[JackleCube]

I am a novice of the woodworking world, admittedly; however, I've recently taken on building myself a desk, to suit my needs. I've used 18mm Plywood, and was wondering what size screws I should use to join the pieces with 'L' corner brackets. Assuming the brackets are between ~1-2mm in thickness, combined with the 18mm of the ply, what screws should I use. Seems the general sizes are 12mm and 16mm, and I was wondering whether using 16mm was cutting it too fine, as I don't want the screw to pierce the surface of the top of the desk. I do however need the desk to be very sturdy, and wasn't sure if 12mm screws are going to go in far enough. Any advice appreciated!

 

[jimmybigfoot]

Personally I would use 16s. They shouldn't penetrate as ur ply is 18+1-2mm of bracket.

 

[Yetty]

Length 16mm sounds about right. Sometimes the length of imperial sized screws give a better match.
Also, if the screw is lightly too long, the tip can be easily nipped-off using side-cutters so that the next size up becomes practical e.g. a 20mm or 3/4 inch length screw.
I guess the real test is check empirically using bracket and piece of offcut!
Hope that helps