Grade 5 Hex Cap Screws have 3 radial lines on the head, and can withstand a minimum of 120,000 PSI tensile strength. Hex Cap Screws feature a washer face under the head, which creates a better seal when applying load. The most common setup for these bolts would contain a Bolt, 2 Flat Washers, Hex Nut or Hex Lock Nut, and/or Split Lock Washer.