Value Collection 581684BR Hex Socket Cap Screw 5/8-18 Unf

Product Description

The VALUE COLLECTION 581684BR is a partially threaded hex socket cap screw designed for high-strength fastening applications in mechanical assemblies, tooling, and industrial equipment. It features a 5/8-18 UNF thread size with a 4.5-inch length under head and is driven by a 1/2-inch hex (Allen) socket. Manufactured from alloy steel with a black oxide finish, this fastener meets ASME/ANSI B18.3 and ASTM A574 standards, making it suitable for demanding load-bearing and vibration-resistant connections. The black oxide coating provides moderate corrosion resistance and a low-reflectance appearance commonly specified in industrial and OEM environments.

This cap screw is used in mechanical maintenance, fabrication, and OEM assembly work where a fine-thread, high-tensile socket cap fastener is required. The 5/8-18 UNF fine thread pitch provides stronger thread engagement and greater resistance to loosening under dynamic or vibrating loads compared to coarse-thread equivalents. Typical applications include machine frames, fixture plates, jigs, hydraulic component mounting, and structural mechanical joints requiring precise torque control. This fastener is sold individually with a minimum order quantity of 10 units.

Key Features

• 5/8-18 UNF fine thread for tight thread engagement and vibration resistance
• 4.5-inch length under head suits deep-clearance fastening applications
• Partially threaded shank provides bearing surface and precise alignment in clearance holes
• Alloy steel construction meets ASTM A574 for high-tensile-strength requirements
• Black oxide finish delivers moderate corrosion resistance and reduced surface glare
• Conforms to ASME/ANSI B18.3 dimensional standards for socket cap screws

Compatibility

Designed as an OEM-style and maintenance replacement hex socket cap screw for applications requiring a 5/8-18 UNF partially threaded fastener with a 1/2-inch hex drive and 4.5-inch length under head.

Installation Notes

Installation should be performed by a qualified mechanic or millwright using a calibrated 1/2-inch hex key or socket driver. Always verify that the mating threaded hole or nut meets the same thread specification (5/8-18 UNF) before installation. De-energize, depressurize, or lock out any equipment per applicable OSHA lockout/tagout procedures before replacing structural fasteners. Do not exceed the recommended seating torque for the joint material and do not reuse fasteners that show signs of thread galling, deformation, or corrosion.