The terminals in the photo above look just like many British terminals. Some of the higher-priced makes (e.g. MK) use a little compression plate on the end of the screw to clamp down on the conductors.
The terminals on British 13A sockets are generally designed to allow for up to three 2.5 sq. mm conductors (permitting a spur cable to be run off a ring from a socket), but there's quite a variation in the size and the design of the surrounding plastic. Some are really a bit of a squeeze for three conductors, while others will take four 2.5s without too much trouble.
Standard "T&E" residential cable here is solid up to the 2.5 size, then stranded for 4 mm and above. Conduit singles are available in both solid and stranded for the 1.5 and 2.5 sizes.
Some cheap sockets skimp on the size of the earth terminal though (where it's an exposed terminal fitted on the metal strap rather than being the same type as the L and N terminals). I've seen some where even two 2.5 stranded conductors is a tight fit.
