Abstract: A disposable surgical knife assembly, a blade for use therein, and a method of manufacture thereof. The blade is manufactured in continuous strip form and may be separated from the strip along score lines in predetermined positions so as to provide the blade with a shape that facilitates accurate and automatic assembly into a holder. The holder is provided with a slot in the forward end to receive the rear portion of the blade, which may be retained in the slot by adhesives or by fusion of the holder material into suitable apertures in the blade. A portion of the blade projects laterally therefrom to facilitate adjustment of the blade position in the holder, said portion being readily broken off after completion of assembly.

Abstract: A lock of the type having an internal plunger with a stem for being gripped by a tool to pull the stem axially to release locking means, in which said stem has a separate portion protruding from the rear end which is spring biased against the forward portion of the stem. When attempts are made by unauthorized persons to open the lock by forcing an elongated member (such as a piece of tubing) into engagement with the protruding portion, the protruding portion is driven back into the forward portion, so that the tubing cannot become engaged therewith.