Value Collection 581244BR Hex Socket Cap Screw 2-4-1/2 Unc

Product Description

The VALUE COLLECTION 581244BR is a heavy-duty hex socket cap screw designed for high-strength fastening applications. Manufactured from alloy steel with a black oxide finish, this screw measures 20 inches in length under the head and is threaded to the 2-4-1/2 UNC standard, making it suitable for large-diameter, coarse-thread installations. The 1-1/2 inch hex drive socket accepts a standard hex key or Allen driver of matching size. It is partially threaded, which is typical for long-body cap screws where a smooth shank provides shear resistance in structural joints. Machinists, millwrights, and heavy equipment technicians are the primary installers of this fastener class.

This screw is used in industrial machinery assembly, structural steel fabrication, and heavy equipment maintenance where large-diameter fasteners are required. The 2-4-1/2 UNC thread designation indicates a 2-inch nominal diameter with 4-1/2 threads per inch, a coarse-thread series suited for thick or tapped-steel applications. The black oxide finish provides moderate corrosion resistance and reduces light reflection in precision equipment environments. Typical install scenarios include press frames, gearbox housings, large conveyor structures, and similar heavy-duty mechanical assemblies.

Key Features

• 2-4-1/2 UNC thread form — 2-inch nominal diameter, 4-1/2 threads per inch coarse series
• 20-inch length under head for deep-reach fastening applications
• Partially threaded shank provides shear strength in structural connections
• 1-1/2 inch hex socket drive for use with standard hex keys or socket drivers
• Alloy steel construction for high tensile and proof load performance
• Black oxide coating for moderate corrosion resistance and reduced surface reflectivity
• Meets ASME/ANSI B18.3 and ASTM A574 fastener standards

Compatibility

Designed as an OEM-style and aftermarket replacement hex socket cap screw for industrial machinery, structural assemblies, and heavy equipment that require a 2-4-1/2 UNC partially threaded fastener with a 1-1/2 inch hex drive.

Installation Notes

Installation of large-diameter socket cap screws of this class is typically performed by millwrights, machinists, or heavy equipment mechanics using calibrated torque tools appropriate for the application. Always de-energize and lock out the equipment before fastener removal or installation per applicable OSHA lockout/tagout procedures. Ensure mating tapped holes meet the UNC 2-4-1/2 thread specification and are clean and free of debris before driving. Do not use impact tools beyond what the joint design specifies, and consult applicable structural or equipment drawings for torque requirements.