SHUT (4)

Shut, n. The act or time of shutting; close; as, the shut of a door. Just then returned at shut of evening flowers. Milton. 2. 2. A door or cover; a shutter. Sir I. Newton.
3. 3. The line or place where two pieces of metal are united by welding.
Cold shut, the imperfection in a casting caused by the flowing of liquid metal upon partially chilled metal; also, the imperfect weld in a forging caused by the inadequate heat of one surface under working.