Heavy-duty forged alloy steel Heat treated fine thread bolt Easily pulls balancer without damaging pulley, shaft, balancer 14 Assorted Bolts: 3 - 5/16" x 18 x 3" 2 - 3/8" x 16 x 3" 3 - 3/8" x 24 x 3" 3 - 8mm x 1.25 x 80mm 3 - 10mm x 1.5 x 75mm