Value Collection 581108PR Hex Socket Cap Screw 3-56 Unf

Product Description

The VALUE COLLECTION 581108PR is a hex socket cap screw designed for precision fastening applications requiring a compact drive profile. This screw features a 3-56 UNF thread specification and measures 1 inch in length under the head. It is partially threaded, making it well-suited for clamping applications where thread engagement length matters. Driven with a 5/64-inch hex key, it delivers reliable torque transfer in tight spaces. Manufactured from alloy steel with a black oxide finish, this fastener meets ASME/ANSI B18.3 and ASTM A574 standards. Machinists, maintenance technicians, and assembly professionals install this screw in machine components, fixtures, and precision equipment.

This cap screw is suited for light-duty to medium-duty mechanical assemblies where a fine-thread UNF fastener is specified. The 3-56 UNF thread pitch provides strong thread engagement in thin materials or tapped holes common in instrumentation housings, small machine frames, and precision fixtures. The black oxide coating offers moderate corrosion resistance and reduces light reflection in optical or electronic assemblies. Partial threading allows the unthreaded shank to bear shear loads, which is useful in close-tolerance bore-and-hole alignments.

Key Features

• 3-56 UNF thread for fine-pitch precision fastening
• 1-inch length under head with partial threading for shear-load applications
• 5/64-inch hex socket drive fits standard Allen keys and hex drivers
• Alloy steel construction meets ASTM A574 mechanical requirements
• Black oxide finish provides moderate corrosion resistance and low-glare surface
• Conforms to ASME/ANSI B18.3 dimensional standards

Compatibility

Designed as a standard ASME/ANSI B18.3 hex socket cap screw for use in any tapped hole or mating hardware calling out a 3-56 UNF thread specification.

Installation Notes

Install using a calibrated 5/64-inch hex key or socket driver. Ensure the receiving tapped hole is clean and free of debris before driving. Follow applicable torque guidelines for ASTM A574 alloy steel fasteners per your assembly specification. Always verify thread engagement depth is sufficient before applying full load.