If you make lamps (or simply repair them on occasion), it’s worth knowing how to make an Underwriters Laboratories approved knot. All commercially sold lamps include a UL-approved knot at the end of the electrical cord within the lamp socket. It’s designed as strain-relief to prevent a yanked cord from disconnecting from the socket, as the knot cannot be pulled through the socket nipple. As shown in the drawing, it’s “knot” hard to tie, so why “knot” use it?
William Stetson, Roanoke, Virginia