Value Collection 215257MSC Carriage Bolt 5/16-18 1 in Grade 8

Product Description

The VALUE COLLECTION 215257MSC is a Grade 8 alloy steel carriage bolt with a 5/16-18 UNC thread and a 1-inch length under head. The square neck beneath the domed head locks into place as the bolt is drawn into wood or soft material, preventing rotation during tightening. A zinc trivalent chromate finish provides corrosion resistance in general-purpose and light outdoor applications. This bolt is fully threaded along the full 1-inch shank length. Installers in mechanical, construction, plumbing support, and electrical mounting applications rely on Grade 8 hardware when higher tensile strength is required over standard Grade 5 or Grade 2 fasteners.

This carriage bolt is suited for wood-to-metal connections, equipment mounting, structural assemblies, and support framing where a smooth, rounded head profile is needed on the finished face. The fully threaded shank allows nut engagement along the entire length, making it practical for thin-material stack-ups. The 5/16-18 thread size is a common fastener dimension across HVAC equipment mounting, panel framing, plumbing support structures, and general trade work. Minimum order quantity is 10 units.

Key Features

• Grade 8 alloy steel construction for high tensile strength in demanding installations
• 5/16-18 UNC fully threaded shank allows nut engagement along the full 1-inch length
• Square neck prevents bolt rotation during tightening without requiring a wrench on the head
• Zinc trivalent chromate finish improves corrosion resistance over standard zinc plating
• Conforms to SAE J429 fastener standard
• Rounded dome head provides a clean, flush appearance on the exposed face

Compatibility

Designed as a standard 5/16-18 UNC carriage bolt for use in any application requiring Grade 8 alloy steel hardware with a square-neck, fully threaded profile and SAE J429 compliance.

Installation Notes

Installation requires a properly sized clearance hole that allows the square neck to seat flush and resist rotation. A standard wrench or socket is applied to the nut side only — no tool contact is needed at the head. Ensure the mating material is suitable for square-neck engagement to prevent the bolt from spinning during torque application. Follow applicable structural or equipment manufacturer torque guidelines for 5/16-18 Grade 8 hardware.