Value Collection 211133PR Flat Socket Cap Screw 1/4-28

Product Description

The VALUE COLLECTION 211133PR is a flat socket cap screw designed for flush or countersunk fastening applications in mechanical assemblies. It features a 1/4-28 UNF thread with a 1-1/2 inch overall length, fully threaded shank, and an 82-degree flat head driven by a 5/32 inch hex socket. The alloy steel construction with black oxide finish provides resistance to corrosion and reduces light reflection in precision applications. This fastener meets ASME/ANSI B18.3 and ASTM F835 standards, making it suitable for demanding structural and mechanical use. Machinists, millwrights, and maintenance technicians commonly install this type of screw.

This flat socket cap screw is used in applications where a low-profile or countersunk head is required to sit flush with or below the mating surface. Common applications include machine tool assemblies, fixtures, jigs, mechanical enclosures, and equipment frames. The fine 1/4-28 UNF thread pitch provides stronger thread engagement and better resistance to vibration loosening compared to coarse-thread equivalents, making it well suited for precision machinery and tight-tolerance assemblies.

Key Features

• 82-degree flat head profile seats flush in standard countersunk holes
• 5/32 inch hex socket drive for secure torque application with an Allen key or hex bit
• 1/4-28 UNF fine thread for improved vibration resistance and thread engagement
• Fully threaded 1-1/2 inch shank provides maximum thread engagement across the full length
• Alloy steel construction meets ASTM F835 for high-strength fastener applications
• Black oxide finish reduces surface corrosion and minimizes light reflection

Compatibility

Designed as an OEM-style replacement or standard fastener for mechanical assemblies requiring a 1/4-28 UNF flat socket cap screw with an 82-degree countersink angle and 5/32 inch hex drive, conforming to ASME/ANSI B18.3.

Installation Notes

Installation is performed by machinists, millwrights, or maintenance technicians using a 5/32 inch hex key or hex socket bit. Ensure the mating material is drilled and countersunk to the correct 82-degree angle before installation. De-energize or lock out equipment per applicable OSHA lockout/tagout procedures before fastener replacement in live machinery. Do not exceed the rated mechanical properties of the fastener by applying impact tools without appropriate torque control.