Value Collection 215518MSC Carriage Bolt 3/8-16 Grade 8

Product Description

The VALUE COLLECTION 215518MSC is a Grade 8 alloy steel carriage bolt designed for high-strength fastening applications. It features a 3/8-16 UNC thread with a 1-3/4 inch length under head, a square neck to prevent rotation during tightening, and a bright uncoated finish. Fully threaded along its entire shank length, this bolt meets SAE J429 standards for mechanical and material properties. The Grade 8 rating indicates high tensile strength, making it appropriate for structural, automotive, and heavy equipment assemblies where fastener integrity under load is critical. Licensed tradespeople and experienced fabricators typically select this bolt where carbon or lower-grade hardware is insufficient.

This carriage bolt is suited for a wide range of industrial, construction, and mechanical applications requiring a secure, tamper-resistant connection through wood, steel, or composite materials. The square neck seats into a mating square hole or bites into wood substrates to resist spin-out as the nut is driven from the opposite side. Common install scenarios include timber framing, trailer construction, machinery mounting, and structural steel connections where Grade 8 strength is specified by design or code.

Key Features

• Grade 8 alloy steel construction for high tensile and proof-load strength per SAE J429
• 3/8-16 UNC thread profile for broad nut and hardware compatibility
• Square neck design locks bolt against rotation during assembly without a wrench on the head
• Fully threaded shank provides maximum thread engagement across the full 1-3/4 inch working length
• Bright uncoated finish suitable for dry indoor environments or secondary coating after installation
• Inch measurement system with length measured under head per standard fastener convention

Compatibility

Designed as a standard-dimension replacement or new-installation carriage bolt compatible with 3/8-16 UNC nuts, washers, and insert hardware conforming to inch-series fastener specifications.

Installation Notes

Installation is typically performed by millwrights, ironworkers, carpenters, or general mechanics using a standard wrench or impact tool on the mating nut. Always insert the bolt from the intended bearing face so the square neck seats fully before applying torque to the nut. Do not weld, grind, or heat-treat the bolt after installation, as this will alter the Grade 8 mechanical properties. Follow applicable structural or mechanical codes for torque requirements based on joint design and load conditions.