Value Collection MP39457 Hex Head Cap Screw 5/8-18 X 4 in Grade 8

Product Description

The VALUE COLLECTION MP39457 is a partially threaded hex head cap screw designed for high-strength fastening applications in industrial, mechanical, and structural assemblies. This fastener measures 5/8-18 (UNF thread) with a 4-inch length under head and is manufactured from Grade 8 steel with a zinc yellow dichromate finish that provides corrosion resistance and a distinctive gold-yellow appearance for identification. Conforming to ASME B18.2.1 standards, this screw is suited for demanding load-bearing connections where a high proof load and shear strength are required. Sold in a package quantity of 10.

This cap screw is used in applications requiring a unified fine thread (UNF) fastener with a high tensile strength rating. Partial threading leaves a smooth shank section near the head, which helps maintain alignment in close-tolerance bores and resists shear forces more effectively than a fully threaded fastener. Typical applications include heavy equipment fabrication, machinery assembly, automotive drivetrain work, and structural mechanical joints where Grade 8 specification is required by design or code.

Key Features

• Grade 8 steel construction provides high tensile and proof load strength for demanding fastening applications
• Zinc yellow dichromate finish offers corrosion resistance and serves as a visual Grade 8 identifier
• Partially threaded shank improves shear resistance and alignment in precision bores
• 5/8-18 UNF thread form for fine-pitch engagement with reduced backlash and vibration loosening
• Meets ASME B18.2.1 dimensional standards for consistent hex head geometry and thread form
• Package quantity of 10 per order

Compatibility

Designed as a standard inch-series hex head cap screw compatible with any 5/8-18 UNF tapped hole or matching hex nut in applications requiring Grade 8 strength and ASME B18.2.1 compliance.

Installation Notes

Installation is performed by a qualified mechanic or millwright using a standard hex wrench or impact socket sized for a 5/8-inch hex head cap screw. Always verify mating thread class and hole depth before installation to avoid cross-threading or bottoming out. Torque to the value specified by the equipment manufacturer or applicable engineering standard for Grade 8 fasteners. Use appropriate thread lubricant or dry torque values as specified by the joint design.