Value Collection C39066 Smooth Flange Bolt 5/8-18 Unf Grade 8

Product Description

The VALUE COLLECTION C39066 is a smooth flange bolt designed for high-strength fastening applications requiring a wide bearing surface and clean flange seat. Sized at 5/8-18 UNF with a 2-1/2 inch length under head, this partially threaded bolt is manufactured from Grade 8 alloy steel, delivering the tensile strength needed in demanding mechanical and structural assemblies. The integrated smooth flange distributes clamping load over a larger area than a standard hex bolt head, reducing the need for a separate washer. The bright, uncoated finish is standard for Grade 8 fasteners used in dry or protected environments.

This bolt is suited for use in heavy equipment, machinery frames, HVAC structural assemblies, plumbing equipment mounts, and other industrial or trade applications where a high-strength UNF fastener with a flange bearing surface is required. Partial threading allows the unthreaded shank to bear shear loads, making it a practical choice where joint alignment and lateral forces are a concern. Installation is typically performed by millwrights, equipment technicians, or field service professionals working on mechanical assemblies.

Key Features

• 5/8-18 UNF thread for fine-pitch high-strength fastening
• 2-1/2 inch length under head for medium-depth through-bolt applications
• Partially threaded shank absorbs shear loads at the joint
• Smooth flange diameter of 1-21/64 inches (1.3281 inches) distributes clamp load without a separate washer
• Grade 8 alloy steel construction meets IFI 111 and SAE J429 standards
• Bright, uncoated finish appropriate for protected or indoor installations

Compatibility

Designed as a standard UNF flange bolt for use in any application requiring a 5/8-18 fine-thread Grade 8 fastener with a smooth flange head, conforming to IFI 111 and SAE J429 specifications.

Installation Notes

Install using a standard hex socket or hex wrench sized for the bolt head. Ensure mating threads are clean and free of debris before installation. Always torque to the Grade 8 specification listed in the applicable equipment service manual or fastener torque standard — do not estimate torque by feel on high-strength fasteners. Minimum order quantity for this SKU is 10 units.