Value Collection 40221 Hex Socket Cap Screw 1/4-28 Unf

Product Description

The VALUE COLLECTION 40221 is a hex socket cap screw designed for secure fastening in applications where a low-profile, high-strength connection is required. Threaded to the 1/4-28 UNF specification, this screw features a 3/16 inch hex drive socket and measures 1-1/2 inches in length under the head. It is partially threaded, which helps resist pull-out forces at the shank and provides positive clamping on the fastened assembly. Manufactured from alloy steel and finished with a black oxide coating, it offers moderate corrosion resistance and a clean appearance. This fastener meets ASME/ANSI B18.3 and ASTM A574 standards.

This screw is suited for general mechanical assembly, tooling, fixtures, and machine components where UNF fine-thread engagement is preferred. Fine threads provide higher tensile strength and better resistance to loosening under vibration compared to coarse-thread equivalents, making this fastener a common choice in precision equipment, hydraulic fittings, and close-tolerance mechanical assemblies. It is installed by machinists, maintenance technicians, and mechanical assemblers across industrial and commercial settings.

Key Features

• 1/4-28 UNF fine thread for high pull-out strength and vibration resistance
• Partially threaded shank improves clamping force and shear strength
• 3/16 inch hex socket drive for use with standard hex keys and Allen wrenches
• Alloy steel construction meets ASTM A574 mechanical requirements
• Black oxide finish provides mild corrosion protection and reduces light reflection
• Conforms to ASME/ANSI B18.3 dimensional standards

Compatibility

Designed as a standard 1/4-28 UNF hex socket cap screw conforming to ASME/ANSI B18.3, compatible with any tapped hole or threaded insert machined to 1/4-28 UNF specifications.

Installation Notes

Install using a 3/16 inch hex key or Allen driver; ensure the mating threaded hole is clean and free of debris before driving. Torque to the assembly specification for the application — do not over-torque alloy steel fasteners in soft or thin material. Black oxide coatings offer only mild corrosion protection; apply a compatible thread lubricant or sealant if the fastener will be exposed to moisture or chemicals. Minimum order quantity for this part is 50 pieces.