i need to fit a security chain to a upvc door what product is best &/or what type of screws do I need to use?

Answer 1

All doors are basicly the same inside. It's only the outer skin that's different.

Use the screws that come with the chain latch, or iff you don't have them, use wood screws just shorter than the door is thick.

You may want to pre-drill them with a small drill bit to avoid splitting the wood, and make it easier to install.

Answer 2

any sheet metal screw will do...even for this