Powerline Hardware P1075 (Millennium Part #527422) is a 2-1/4 in x 2-1/4 in square washer drilled for 5/8 in machine bolts and built to Bellcore Specification 6150. Square washers spread bolt load across the wood fiber of a utility pole so the nut does not crush or pull through under strand tension, guy load or cyclic wind. Line crews install them under nuts and bolt heads on through-bolted attachments for strand clamps, guy hardware and messenger fittings. Keep the 5/8 in size stocked in bulk on aerial jobs, since nearly every pole framing detail in a fiber or joint-use build calls for it.