Value Collection 489046PS Carriage Bolt 5/16-18 1-1/2 in Grade 2

Product Description

The VALUE COLLECTION 489046PS is a 5/16-18 UNC carriage bolt with a 1-1/2 inch length under head and a square neck design. Made from Grade 2 steel with a zinc-plated finish, this fastener is built for general-purpose mechanical and structural assembly work. The square neck locks into wood or soft substrate to prevent rotation during installation, eliminating the need for a wrench on the bolt end. It meets ASTM A307 standards, making it a recognized choice for light-to-moderate load fastening applications. Electricians, plumbers, HVAC techs, and general contractors reach for this size when securing equipment frames, mounting brackets, and utility supports.

This carriage bolt is suited for residential and light commercial applications where a through-bolt with a finished, dome-shaped head is required. Common install scenarios include securing junction boxes, conduit hangers, equipment pads, and structural framing connections. The zinc plating provides basic corrosion resistance in dry or mildly humid indoor environments. Sold in a minimum order quantity of 100 pieces per order, making it appropriate for stocking a service van or supply room.

Key Features

• 5/16-18 UNC thread size for broad hardware compatibility
• 1-1/2 inch length under head for standard through-fastening depth
• Square neck prevents bolt rotation during nut tightening without additional tooling on the bolt head
• Grade 2 steel construction meets ASTM A307 fastener standards
• Zinc-plated finish provides basic corrosion resistance in dry indoor environments
• Rounded dome head delivers a clean, flush-face appearance on the exposed side

Compatibility

Designed as a general-purpose replacement or stock fastener for any application requiring a 5/16-18 UNC carriage bolt with a 1-1/2 inch length under head and square neck, conforming to ASTM A307 standards.

Installation Notes

Install using a standard wrench or socket on the nut side only — the square neck seats into the material to hold the bolt stationary. Always drill a clearance hole sized to allow the square neck to seat fully before tightening. Follow applicable structural or mechanical codes when using in load-bearing connections. Inspect threads and plating for damage before installation; do not use fasteners with stripped threads or compromised coating in structural applications.