Value Collection 581378PR Hex Socket Cap Screw 1/4-20 Unc

Product Description

The VALUE COLLECTION 581378PR is a hex socket cap screw designed for high-strength fastening applications in mechanical assemblies, tooling fixtures, and industrial equipment. It features a 1/4-20 UNC thread size and measures 3-3/4 inches in length under the head. The 3/16-inch hex drive accepts a standard hex key or Allen wrench for installation and removal. Manufactured from alloy steel with a black oxide finish, this fastener provides good tensile strength and moderate corrosion resistance for indoor and protected-environment use. It is partially threaded, which helps maintain clamping force across thick material joints. Machinists, millwrights, and maintenance technicians are the typical installers.

This screw is suited for use in production machinery, machine tool setups, jigs, dies, and structural mechanical assemblies where a low-profile socket head fastener is required. The 1/4-20 UNC coarse thread pitch is widely used in general-purpose industrial and mechanical applications. Partial threading on a 3-3/4-inch length allows this fastener to pass through clearance holes before engaging a tapped bore, making it appropriate for clamping or alignment work in moderately thick assemblies.

Key Features

• 1/4-20 UNC thread for broad compatibility with standard tapped holes
• 3-3/4 inch length under head suits thicker material stacks and clamped assemblies
• 3/16-inch hex socket drive for use with standard hex keys
• Alloy steel construction for high tensile and shear strength
• Black oxide finish provides mild corrosion resistance and reduces light reflection
• Partially threaded shank maintains clamping integrity in thick-section joints
• Meets ASME/ANSI B18.3 and ASTM A574 standards

Compatibility

Designed as a standard ASME/ANSI B18.3 hex socket cap screw for use in any 1/4-20 UNC tapped hole application requiring a 3-3/4-inch partially threaded alloy steel fastener.

Installation Notes

Installation is performed using a 3/16-inch hex key or T-handle hex driver. Ensure the mating tapped hole meets 1/4-20 UNC thread specifications and is free of debris before driving the fastener. Follow applicable torque guidelines for alloy steel socket cap screws per your assembly specifications. Black oxide finish is not a heavy-duty corrosion barrier; avoid prolonged exposure to moisture or corrosive environments without additional protection.