Bolt Kit - 12pt 5pk 5/16-18 x .560

The Bolt Kit - 12pt 5pk 5/16-18 x .560 is a premium fastener set engineered for serious automotive builders and engine rebuilds. Whether you're assembling a high-performance stroker motor, installing cylinder heads on a fresh block, or restoring a classic vehicle, these bolts deliver the precision and reliability that separates professional-grade work from amateur shortcuts. ARP's reputation in the fastener world exists because critical joints demand bolts that won't fail under extreme combustion pressures, thermal cycling, and vibration.

These 12-point head bolts feature a 5/16-18 thread specification with a .560-inch length, making them ideal for manifold mounting, accessory brackets, and precision fastening applications where a six-pack of standard hex bolts won't cut it. The 12-point head geometry distributes load more evenly than traditional six-point designs and reduces the risk of bolt rounding when torque specifications demand accuracy—critical in fuel injection systems, alternator mounts, and intake manifold applications. The five-piece kit provides exactly what you need for common engine bay installations without excess inventory, and the compact 3.85 x 0.65 x 5.9-inch package fits easily in your toolbox or tech bag.

Mechanics and engine builders trust ARP bolts for restorations, turbo upgrades, and original equipment repairs where bolt stretch or failure would mean catastrophic engine damage. The 5/16-18 size works across domestic and import platforms—from vintage muscle cars to modern performance builds. Always verify thread pitch and length against your specific application, and follow factory torque specifications during installation; quality fasteners only perform as intended when properly installed and maintained.