Engineered for strength and reliability, the Hex Head Cap Screws Grade 8 Steel Plain 5/16-18 x 4 delivers high-torque performance for demanding assemblies. Crafted from Grade 8 steel with a plain (unplated) finish, these screws provide superior tensile strength and durability for mechanical, automotive, and industrial applications.

Designed for high-load fastening, these hex head cap screws resist loosening under vibration and heavy use, making them ideal for critical equipment assemblies and maintenance projects.

Specifications

• Head type: Hex
• Material: Grade 8 steel
• Finish: Plain (unplated)
• Diameter: 5/16 in
• Thread pitch: 18 TPI (5/16-18 UNC)
• Length: 4 in
• Usage: Hex Head Cap Screws

Applications

Ideal for machinery, automotive repair, equipment mounting, and construction projects that demand a strong, dependable fastener.

Installation and care

• Compatibility: Use with nuts and washers rated for 5/16-18 threads.
• Torque: Apply torque per standard Grade 8 fastener guidelines to achieve proper clamping force without over-tightening.