These are 1/2" Left Hand Fine Thread Blade Mounting Bolts for King Kutter Finish Mowers Fits 4', 5;, 6; and 7' cut mowers Set of Three (3) Blade Mounting Bolts with Washers Compatible Replacement for King Kutter Code 502310. Fits RFM Series Finish Mowers. These are 1/2" Left Hand Fine Thread Blade Mounting Bolts for King Kutter Finish Mowers. Fits 4', 5;, 6; and 7' cut mowers