Knife Bolt for Polar 55, Polar 55 EM, Polar 58 E, Polar 58 EM, Polar 66, Polar Power Max 28, Polar 71 and most of the Polar 72 (28") Paper Cutters (equivalent to the original Polar part numbers 013551, 014775, 014776, 021054, and 200276) Socket head cap screw, 10mm diameter thread by 17mm long (.67") below the washer. It has a 1" diameter washer which is 1/4" thick and has been counter bored 1/16" deep to fit the head of the bolt. The washer is held captive by a snap ring. See our part number B521 for a longer version of this same bolt. Order these by the bolt length under the washer, not by the Polar model number.