Lawnmower blades for lawn mowers MTD YARD MAN GUTBORD FOR SUPER18 , SUPER18-117N MODELS MODEL - TECHNICAL SPECIFICATIONS LENGTH 360 mm CENTRAL BORE 10 mm OUTSIDE BORE 7.9 mm CENTRAL BORE INDEX 63.5 mm CODE: 13270310 ORIGINAL CODE 742-0486 , 942-0486 SR