5/8-11 x 2-1/4 Inch Coarse Plain Grade 8 Dome Head Plow BoltThese Grade 8 plow bucket tooth bolts have a locking key that holds the bolt as the nut is fastened. Used to secure heavy equipment parts, these bolts have smooth, angled heads to sit flush within their countersunk holes. The hole must first be countersunk with the chamfered edge in order to sit flush. These bolts come in a black oxide finish, which is corrosion resistant in dry environments.