Value Collection 215358MSC Carriage Bolt 5/16-18 2-1/2 in Grade 8

Product Description

The VALUE COLLECTION 215358MSC is a Grade 8 alloy steel carriage bolt intended for high-strength fastening applications across industrial, structural, and mechanical assemblies. It features a 5/16-18 UNC thread with a 2-1/2 inch length under the head and a square neck that locks into place in pre-drilled square or wood substrates, preventing rotation during nut tightening. The bolt is fully threaded along its entire 2-1/2 inch shank and carries an uncoated bright finish. Grade 8 alloy steel construction meets SAE J429, making it suitable for demanding load-bearing connections. Machinists, millwrights, maintenance technicians, and structural assemblers commonly specify this fastener where a flush, rotation-resistant bolt head is required.

This carriage bolt is used in residential and commercial construction, equipment fabrication, and general structural assembly where a low-profile dome head and anti-rotation square neck are needed. The 5/16-18 UNC thread pattern is a common imperial pitch, compatible with standard hex nuts and washers in the same thread family. Fully threaded construction allows nut positioning anywhere along the shank, adding flexibility in variable-thickness material stacks.

Key Features

• Grade 8 alloy steel construction meets SAE J429 strength standards
• 5/16-18 UNC fully threaded shank for flexible nut positioning
• Square neck design resists rotation during installation without a wrench on the head
• 2-1/2 inch length under head suits medium-depth fastening applications
• Bright uncoated finish with no added coating thickness to affect dimensional fit
• UNSPSC Code 31161603 for procurement and catalog classification

Compatibility

Designed for use with standard 5/16-18 UNC hex nuts and washers in inch-system fastener assemblies conforming to SAE J429 specifications.

Installation Notes

Installation is performed by trades or technicians working with structural or mechanical assemblies. Power down or de-energize any associated equipment before working in the fastening area. Insert the bolt through a pre-drilled hole sized to seat the square neck flush, preventing spin, then thread a compatible nut from the opposite side and torque per the applicable engineering specification or governing structural code. Do not use an impact tool directly on the dome head, as this can damage the head profile or displace the square neck seat.