This is a A-50030946 Locknut, Disc Mower Blade PN: 50030946Main Description As Following : A-50030946 Locknut, Disc Mower Blade PN: 50030946 Found in Section & Models : Hay Tool Parts > Disc Mower Blade Bolts & Nuts, Bush Hog MOWER, DISC: HM2007, Bush Hog MOWER, DISC: HM2008, Bush Hog MOWER, DISC: HM2009, Bush Hog MOWER, DISC: HM2407, Bush Hog MOWER, DISC: HM2408, Bush Hog MOWER, DISC: HM2409 Associated Items : A-50030318, A-50030319, A-50030944 Also This is An Aftermarket Product And : Thread Size: M12 X 1.75