17" fluted coulter with special punching to fit Blu-Jet, Crustbuster, Great Plains, Case-IH 5400, John Deere 1570, Landoll, Sukup/Marliss, Tye, Yetter, and others. Blade is .177" thick and made of super tough Boron steel. Excellent quality blade.17" diameter, 5/16" wide, .177" thick. 4 hole pattern, 4" center hole, slotted holes to fit both 5" and 5-1/4" bolt circle