The previous examples given for finding face-moulds are intended for moulded rails. For round rails the same process is to be followed, with this difference: that instead of finding curves on the face-mould for the sides of the rail, find one for a centre-line and describe circles upon it, as at Fig. 145; then trace the sides of the mould by the points so found. The thickness of stuff for the twists of a round rail is the same as for the straight part. The twists are to be sawed square through.