Value Collection 721326BR Flat Socket Cap Screw 1-8x4.5in

Product Description

The VALUE COLLECTION 721326BR is a flat socket cap screw designed for applications requiring a flush or countersunk head profile. The 82-degree flat head seats cleanly into countersunk holes, keeping the fastener surface flush with the workpiece. Drive engagement is through a 5/8-inch hex socket. The screw is 4-1/2 inches in overall length with a 1-8 UNC thread and is partially threaded. Constructed from alloy steel with a black oxide finish, it offers solid mechanical strength and basic corrosion resistance. Licensed tradespeople and experienced machinists use this fastener in structural, tooling, and mechanical assembly applications where a low-profile head is required.

This flat socket cap screw is suited for use in general industrial, mechanical, and structural assembly settings. The 1-8 UNC thread size and 4-1/2-inch overall length make it appropriate for thicker stock or through-bolt applications where partial threading is preferred to allow for bearing against the shank. The black oxide finish helps reduce galling and provides light surface protection in dry or lightly oiled environments. It is sold individually and meets ASME/ANSI B18.3 and ASTM F835 fastener standards.

Key Features

• 82-degree flat head for flush countersunk seating
• 5/8-inch hex socket drive for high-torque installation with a standard hex key or Allen driver
• 1-8 UNC thread standard, partially threaded along the 4-1/2-inch overall length
• Alloy steel construction for high tensile strength in demanding assembly applications
• Black oxide finish provides light corrosion resistance and reduces light reflection
• Meets ASME/ANSI B18.3 and ASTM F835 dimensional and performance standards

Compatibility

Designed as a standard inch-series flat socket cap screw for use in countersunk holes sized and toleranced to ASME/ANSI B18.3 specifications for 1-8 UNC thread fasteners.

Installation Notes

Installation is typically performed by machinists, millwrights, or mechanical assemblers using a calibrated hex key or T-handle Allen driver sized to the 5/8-inch socket. Countersunk hole geometry must match the 82-degree included angle to achieve proper head seating. Do not overtighten in soft base materials, as the flat head geometry concentrates clamping load differently than a standard cap screw. Power down or de-energize any associated equipment before fastener removal or replacement in live assemblies.