Cut-off
A cut-off in founding is somewhat different to that in engineering, and means to arrange a riser in such a manner as will prevent the full head of pressure from being exerted on the mould. To do this effectually and with absolute certainty, the riser should instantly indicate when the mould is full, at which point the head-pressure in the running basin is at once checked by ceasing to pour. What remains in the basin flows through the castings, and out at the riser, which, being lower, tends to "cut off" just as much pressure as the difference in depth measures. See RISER; WEIGHTING-COPES; PRESSURE OF MOLTEN METAL.