Value Collection 489047PS Carriage Bolt 5/16-18 1-3/4 in Grade 2

Product Description

The VALUE COLLECTION 489047PS is a Grade 2 steel carriage bolt with a 5/16-18 UNC thread and a 1-3/4 inch length under head. It features a square neck that self-locks into wood or soft material when driven, preventing rotation without a secondary tool. The zinc plating provides basic corrosion resistance for general-purpose fastening applications. This bolt conforms to ASTM A307 standards, making it a recognized choice for low-carbon steel fastener applications across construction, woodworking, and light structural assemblies. Electricians, plumbers, HVAC technicians, and general contractors commonly reach for this fastener when securing equipment supports, framing connections, and fixture mounts.

This carriage bolt is suited for residential and light commercial installations where a flush, round-head fastener with a self-locking neck is required. Typical applications include securing lumber framing, equipment mounting brackets, and utility supports. The 5/16-18 UNC thread is one of the most common sizes in trade work, fitting standard hex nuts, wing nuts, and coupling nuts of the same thread designation. The zinc finish makes it appropriate for dry to mildly humid interior environments.

Key Features

• 5/16-18 UNC thread for compatibility with standard inch-series nuts and hardware
• Square neck locks into substrate material to resist rotation during installation
• Grade 2 steel construction meets ASTM A307 fastener standards
• Zinc plating provides basic corrosion resistance for interior and sheltered applications
• 1-3/4 inch length under head suits a range of thin-to-moderate material stack-ups

Compatibility

Designed as a standard inch-series carriage bolt compatible with 5/16-18 UNC hex nuts, washers, and coupling hardware used in general construction and trade fastening applications.

Installation Notes

Installation is typically performed with a standard hammer to seat the square neck flush into the substrate, preventing spin during nut tightening. Apply a flat washer and hex nut on the threaded end and tighten with a wrench or socket to the appropriate snug-tight condition for the application. Do not use impact drivers directly on the bolt head, as the round head is not designed for driven torque. Ensure the substrate material is appropriate for the zinc finish rating before installation in wet or outdoor-exposed locations.