A flange for securing a rotary blade to a shaft that includes a solid plate with: an axially oriented shaft hole substantially in the center of the plate; two or more additional blade holes for securing a blade to the flange; an embossment around the shaft hole, providing a profile for stopping blade rotation about the blade hole; and a depression on the back face of the plate opposite the embossment, which provides a welding surface to secure the plate to a shaft passing through the shaft hole. Also are assemblages that include a flange, such as a blade assembly system for attaching two or more blades to a shaft, a bladed shaft, an attachable farm implement including a bladed shaft, and a powered machine, which includes a bladed shaft.