SPIDER BALE SPEAR. A well built hay spear is essential on the farm. Our hay spear attachment is built for optimum stability. The bottom two spears, supporting the round bales, are made from 1018 cold rolled steel. The center bale spear is one piece of solid forged steel. The two spears on the square bale spear is one piece of solid forged steel. The frame is constructed of 3” x 3” square tube, making the SPIDER Hay Spear a very rugged piece if equipment.