They’re called Tubular latches and the dimension you need is the backset - the distance from the faceplate to the centre of the spindle hole.
The spindle hole will be 8mm although there are still imperial sized ones around (shudder) which are half a mm smaller.
Window locks use a smaller size again 6mm (?).
They’re called Tubular latches and the dimension you need is the backset - the distance from the faceplate to the centre of the spindle hole.
The spindle hole will be 8mm although there are still imperial sized ones around (shudder) which are half a mm smaller.
Window locks use a smaller size again 6mm (?).