Hex Head Bolt 3/8-16 x 4 Grade 5 5pk

The ALLSTAR PERFORMANCE Hex Head Bolt 3/8-16 x 4 Grade 5 is a precision fastener engineered for high-strength mechanical assembly in demanding applications. This 5-pack of Grade 5 steel hex bolts delivers the tensile strength and shear resistance required in automotive, powersports, and machinery repair work where fastener integrity is non-negotiable. The 3/8-16 thread pitch and 4-inch length make these bolts suitable for engine block work, suspension brackets, and structural frame reinforcement across a wide range of platforms.

Grade 5 classification guarantees a minimum tensile strength of 120,000 PSI—substantially higher than Grade 2 fasteners—making these bolts resistant to vibration-induced loosening and capable of handling repeated stress cycles. The 9/16-inch hex head provides a standard wrench and socket fit, ensuring compatibility with common hand tools and pneumatic impact guns used in field repairs and professional shops. Zinc oxide plating protects against corrosion while maintaining dimensional accuracy for reliable torque values and zero-play assembly. The 3/8-16 thread specification aligns with SAE and metric conversion standards, making cross-reference sourcing straightforward for technicians.

These bolts serve technicians performing engine rebuilds, transmission bracket installation, suspension geometry work, and powersports frame repair. The 5-pack quantity is sized for single-job applications—a typical engine block head stud replacement or frame reinforcement project—reducing excess inventory while ensuring genuine Grade 5 specification throughout the kit. Operators working in corrosive environments or high-temperature conditions benefit from the corrosion-resistant coating, which extends fastener lifespan in salt-air or wet storage scenarios.

Grade 5 bolts represent the industry standard where load-bearing integrity and fatigue resistance matter. Unlike lower-grade fasteners, these resist stretching under sustained pressure and maintain clamping force through thermal cycling—critical in engine compartments and high-vibration assemblies. The ALLSTAR PERFORMANCE line is recognized across automotive and motorsports communities for consistent metallurgical quality and precise dimensional tolerances that ensure repeatable assembly results.