Value Collection 721030PR Flat Socket Cap Screw 4-40

Product Description

The VALUE COLLECTION 721030PR is a flat socket cap screw designed for low-profile fastening applications in metal assemblies and precision mechanical work. It features a 4-40 UNC thread and measures 3/16 inches in overall length. The 82-degree flat head countersinks flush with or below the surface, eliminating protrusions that could interfere with mating components. Drive engagement is through a 1/16-inch hex socket, requiring an appropriately sized hex key or Allen driver. The screw is manufactured from alloy steel with a black oxide finish that provides moderate corrosion resistance and reduces light reflection. This part conforms to ASME/ANSI B18.3 and ASTM F835 standards. Machinists, assembly technicians, and maintenance professionals typically install this fastener.

This screw is suited for tight-clearance installations where a standard socket cap head would protrude above the work surface. Common applications include instrument panels, fixture plates, jigs, machine guards, electronics enclosures, and general industrial assemblies requiring a flush or recessed fastener profile. The 4-40 thread size targets fine-pitch applications typical of light-gauge metal parts, thin panels, and small mechanical subassemblies. The fully threaded shank provides maximum thread engagement for the full grip length, which is advantageous in shallow-tapped holes common in this thread size range.

Key Features

• 82-degree flat head countersink profile for flush or below-surface installation
• 1/16-inch hex socket drive for precise torque application in tight spaces
• Fully threaded shank maximizes thread engagement across the entire 3/16-inch length
• Alloy steel construction provides strength suitable for general industrial fastening
• Black oxide finish reduces surface reflectivity and offers mild corrosion resistance
• Conforms to ASME/ANSI B18.3 and ASTM F835 fastener standards

Compatibility

Designed as a standard-dimension flat socket cap screw for use in any application requiring a 4-40 UNC thread with an 82-degree countersunk flat head per ASME/ANSI B18.3 specifications.

Installation Notes

Installation requires a properly sized countersunk hole to match the 82-degree flat head geometry; verify the mating material is tapped or clearance-drilled to the correct 4-40 specification before driving. Use a calibrated 1/16-inch hex key or Allen driver to avoid rounding the socket recess, particularly at this small drive size. De-energize or lock out any equipment before performing fastener installation or replacement in live assemblies. Follow applicable mechanical and electrical codes for the specific application and industry.