Value Collection D30170-31/2 Hex Cap Screw 1-8 X 3.5 in Grade 5

Product Description

The VALUE COLLECTION D30170-31/2 is a partially threaded hex head cap screw designed for heavy-duty bolted connections in industrial, mechanical, and structural applications. Manufactured from Grade 5 steel with a zinc-plated finish for corrosion resistance, this fastener features a 1-8 UNC thread and a 3.5-inch length under head. It conforms to ASME B18.2.1 dimensional standards, making it a reliable choice wherever a specification-grade inch-series cap screw is required. Maintenance technicians, millwrights, and mechanical contractors rely on fasteners like this for equipment assembly, machinery repair, and structural bolting work.

This cap screw is suited for general-purpose bolting in residential, commercial, and industrial settings. The partial threading allows for a smooth shank grip length, which is advantageous in applications requiring precise clamping without thread engagement across the full joint. Typical uses include equipment mounting, bracket fabrication, and machinery assembly where Grade 5 tensile strength and ASME-compliant dimensions are specified.

Key Features

• Grade 5 steel construction for medium-to-high tensile strength bolting applications
• Zinc-plated finish provides baseline corrosion protection in dry or mildly humid environments
• Partially threaded shank allows full-grip clamping across the joint interface
• UNC (Unified National Coarse) thread form for broad nut and tapped-hole compatibility
• Conforms to ASME B18.2.1 for consistent dimensional and tolerance compliance
• Inch measurement system — 1-8 thread size, 3.5 inches length under head

Compatibility

Designed as a standard inch-series hex head cap screw compatible with 1-8 UNC nuts, threaded inserts, and tapped holes conforming to Unified National Coarse thread standards per ASME B18.2.1.

Installation Notes

Installation is typically performed by millwrights, maintenance mechanics, or mechanical contractors using standard hex wrenches or impact tooling sized for the hex head drive. Always de-energize and lock out equipment before fastener service on live machinery. Torque to the value specified in the applicable engineering drawing or equipment service manual — do not assume a torque value from fastener grade alone. Verify that mating nuts or tapped holes are clean, undamaged, and rated for 1-8 UNC thread engagement before assembly.