[100 PKG] Hex Head Cap Screws Grade 8 Steel Plain (USA Made) 5/16-18 x 5/8

Engineered for strength and reliability, these Hex Head Cap Screws Grade 8 Steel Plain (USA Made) 5/16-18 x 5/8 deliver heavy-duty performance for demanding assemblies. Crafted from high-tensile Grade 8 steel and finished plain for rugged, uncoated strength, these screws are ideal for industrial equipment, automotive repairs, and structural applications. Made in the USA, they meet strict quality standards to ensure consistent performance under load.

Key specifications

• Head style: Hex head cap screw
• Grade: 8
• Material: Steel
• Finish: Plain (uncoated)
• Thread size: 5/16-18 UNC
• Length: 5/8 in
• Drive: Hex
• Country of origin: USA Made

Applications include heavy machinery, automotive assembly, equipment maintenance, and structural fastenings where high strength and reliability are essential. The plain finish offers robust performance in clean environments and accepts surface treatments later if needed. For best results, pair with compatible nuts or tapped holes designed for 5/16-18 threads and consult your torque specifications for the recommended clamping force.

Why choose these fasteners?

• Superior strength: Grade 8 steel for high tensile load
• USA made: Quality you can trust
• Plain finish: Uncoated core for versatile use
• Precise thread: 5/16-18 ensures reliable fit and torque transfer