Value Collection 581582PS Hex Socket Cap Screw 1/2-20 Unf

Product Description

The VALUE COLLECTION 581582PS is a hex socket cap screw designed for high-strength fastening applications in mechanical assemblies, tooling fixtures, and equipment maintenance. The screw features a 1/2-20 UNF thread size and measures 1.375 inches in length under the head, with full threading along the entire shank. Drive engagement is made with a 3/8-inch hex key. Constructed from alloy steel with a black oxide finish, the fastener delivers solid corrosion resistance and meets the dimensional and mechanical requirements of ASME/ANSI B18.3 and ASTM A574. This type of fastener is installed by machinists, millwrights, field technicians, and maintenance mechanics across industrial and commercial service environments.

The 581582PS is suited for applications requiring a strong, recessed-drive cap screw in close-tolerance assemblies. The fine 1/2-20 UNF thread pitch provides tighter clamping control and greater resistance to vibration-induced loosening compared to coarse-thread alternatives. Typical use cases include machine frames, hydraulic component mounting, fixture plates, and structural mechanical joints where a flush or countersunk fastener head is required. The black oxide finish reduces light reflection and provides a degree of surface protection in dry or lightly oiled service conditions.

Key Features

• 1/2-20 UNF fine thread for precise clamping and vibration resistance
• Fully threaded shank, 1.375 inches in length under head
• 3/8-inch hex drive for standard Allen key or hex bit engagement
• Alloy steel construction rated to ASTM A574 mechanical requirements
• Black oxide finish for surface protection and low-reflectance appearance
• Conforms to ASME/ANSI B18.3 dimensional standards

Compatibility

Designed as a standard ASME/ANSI B18.3 hex socket cap screw suitable for any application requiring a 1/2-20 UNF fully threaded fastener with a 3/8-inch hex drive and 1.375-inch length under head.

Installation Notes

Installation is performed with a 3/8-inch hex key or Allen-drive bit. Always ensure the mating threaded hole is clean, properly tapped to 1/2-20 UNF, and free of debris before installation. Power down or de-energize any equipment before fastener service work begins. Do not exceed the torque rating specified by the equipment manufacturer for the joint being assembled.