5/16-24 x .400" 12pt. Hemi cam gear to cam hub bolt. These bolts are aircraft quality, made from heat treated steel and black oxide finish. These bolts are designed with a shoulder to register the cam gear to the cam hub to act like a dowel pin and give the cam gear to cam hub the most precise fit possible. Bolts are sold individual. Most RCD gear drives that use seven bolts to hold the cam gear to the cam hub these bolts work well for and they can be used on KB, Casale, or Fowler gear drives. Bolts have a 3/8" twelve point wrench head with a weight reduction hole in it and a .125" shoulder.