Value Collection 215318MSC Carriage Bolt 5/16-18 Grade 8

Product Description

The VALUE COLLECTION 215318MSC is a Grade 8 alloy steel carriage bolt with a 5/16-18 UNC thread and a 1-3/4 inch length under head. Carriage bolts feature a domed head and a square neck that pulls into the material during installation, preventing rotation without a wrench on the bolt head. This fastener is fully threaded along its 1-3/4 inch shank and carries an uncoated, bright finish. Conforming to SAE J429 standards, Grade 8 alloy steel provides high tensile strength suitable for demanding structural and mechanical fastening applications. Licensed tradespeople and maintenance professionals install these fasteners in a wide range of assemblies requiring secure, tamper-resistant clamping.

This carriage bolt is suited for structural wood-to-wood, wood-to-metal, and general mechanical assemblies in residential and light commercial construction and maintenance applications. The square neck seats into a pre-drilled square or round hole in wood or soft material, locking the bolt in place while a nut is tightened from the opposite side. Its fully threaded shank allows full engagement across a range of material thicknesses up to 1-3/4 inches under head. These fasteners are commonly used by carpenters, ironworkers, maintenance technicians, and general contractors wherever high-strength, round-head fasteners are specified.

Key Features

• Grade 8 alloy steel construction for high tensile strength and durability
• Fully threaded 5/16-18 UNC shank, 1-3/4 inches length under head
• Square neck prevents rotation during nut tightening without a secondary tool on the bolt
• Uncoated bright finish — suitable for dry interior applications or where a coating will be applied after installation
• Conforms to SAE J429 fastener standard
• Inch system of measurement for compatibility with standard UNC tooling and hardware

Compatibility

Designed as a standard UNC 5/16-18 carriage bolt for use with any 5/16-18 compatible hex nut and washer in wood, structural, or general mechanical assemblies requiring SAE J429 Grade 8 fasteners.

Installation Notes

Installation is performed by tradespeople or maintenance technicians using standard hand tools. Before installation, ensure the mating hole is sized correctly to allow the square neck to seat flush and prevent bolt rotation. Tighten the nut from the opposite face only — applying torque directly to the domed head will damage the fastener. Follow applicable building codes, structural specifications, and torque guidelines provided by the assembly designer or engineer of record.