Value Collection 721051PR Flat Socket Cap Screw 5-40

Product Description

The VALUE COLLECTION 721051PR is a flat socket cap screw designed for low-profile fastening applications where a flush or countersunk head is required. Sized at 5-40 UNC x 1.5 inches overall length, it features an 82-degree flat head with a 5/64 inch hex socket drive. Constructed from alloy steel with a black oxide finish, the fastener offers good hardness and mild corrosion resistance suitable for controlled indoor environments. The shank is partially threaded, allowing for precise clamping force in through-bolt and standoff applications. Licensed trades and precision machinists specify this type of fastener where a standard button or pan head would interfere with mating components.

This screw is used in mechanical assemblies, jigs, fixtures, tooling plates, and machine frames where a flush-mount fastener is required. The 5-40 thread size targets small precision assemblies common in instrumentation, electronics enclosures, and light mechanical hardware. The partial thread design is appropriate for applications that require an unthreaded shank to bear shear loads or maintain accurate hole alignment. Installation is performed with a 5/64 inch hex key or T-handle driver.

Key Features

• 82-degree flat head profile allows flush or countersunk installation in mating surfaces
• 5-40 UNC thread form for compatibility with standard small-pitch inch-series tapped holes
• 5/64 inch hex socket drive for precise torque application with standard Allen wrenches
• Partially threaded shank supports shear load and accurate part alignment
• Alloy steel construction provides higher tensile strength than standard carbon steel fasteners
• Black oxide finish reduces light reflection and offers mild surface protection in dry environments

Compatibility

Designed as an inch-series replacement or service fastener for assemblies using 5-40 UNC flat socket cap screws per ASME/ANSI B18.3 and ASTM F835 standards.

Installation Notes

Installation requires a matching countersunk hole to achieve the flush seating an 82-degree flat head demands. Use a calibrated hex key or torque driver sized at 5/64 inch. Verify the tapped hole thread class matches the fastener before driving to avoid galling or cross-threading. Degrease mating surfaces and inspect threads for damage prior to assembly; black oxide does not provide meaningful corrosion protection in wet or outdoor environments.