Value Collection 99045 5/16-18 X 6 in Grade 8 Hex Cap Screw 50pk

Product Description

The VALUE COLLECTION 99045 is a partially threaded hex head cap screw designed for high-strength fastening applications. Manufactured from Grade 8 steel in an uncoated finish, this fastener measures 5/16-18 thread size with a 6-inch length under head. Grade 8 steel delivers a higher tensile strength than Grades 2 and 5, making it well suited for demanding mechanical assemblies where bolt stretch and shear resistance matter. The Unified National Coarse (UNC) thread form provides reliable engagement in standard tapped holes and nuts. This screw conforms to ASME B18.2.1, the governing standard for inch-series hex cap screws.

This fastener is used across a wide range of industrial, commercial, and mechanical applications requiring a strong, reliable bolted connection. Typical uses include structural assemblies, equipment mounting, machinery frames, and heavy-duty brackets. The partial threading allows for a smooth shank section, which resists shear loads more effectively than a fully threaded fastener of the same size. It is installed by mechanics, millwrights, HVAC equipment technicians, and general tradespeople wherever a 5/16-18 UNC bolted connection is specified.

Key Features

• Grade 8 steel construction for high tensile and proof load strength
• 5/16-18 UNC thread form for compatibility with standard tapped holes and hex nuts
• 6-inch length under head suits long-reach and thick-stack fastening applications
• Partially threaded shank improves shear resistance compared to full-thread designs
• Uncoated finish — no added plating or coating that could affect dimensional tolerances
• Meets ASME B18.2.1 dimensional standards for inch-series hex cap screws

Compatibility

Designed as a standard inch-series hex head cap screw for use with 5/16-18 UNC tapped holes, standard hex nuts, and flat washers in any assembly calling out a Grade 8 fastener to ASME B18.2.1.

Installation Notes

Installation should be performed by a qualified mechanic or tradesperson using an appropriate hex drive socket or wrench sized for the head. Always power down or de-energize equipment before fastener work on live mechanical assemblies. Apply a calibrated torque wrench to reach the fastener specification called out in the equipment service manual — do not estimate final torque by feel on Grade 8 hardware. Inspect threads in the mating hole for damage or contamination before installation to avoid cross-threading or false torque readings.