Bowmalloy 36040 Hex Head Cap Screw 5/16-18 X 4 in Grade 9

Product Description

The BOWMALLOY 36040 is a Grade 9 alloy steel hex head cap screw with a 5/16-18 thread size and a 4-inch length under head. It features a zinc-plated clear chromate finish for corrosion resistance in demanding environments. The partial threading pattern provides clamping force across a range of joint thicknesses. This fastener is installed by electricians, HVAC technicians, plumbers, and general contractors wherever a high-strength inch-series hex cap screw is required.

This screw is suited for mechanical assemblies, equipment mounting, and structural connections in both residential and commercial applications. The 5/16-18 coarse thread engages quickly and holds reliably in steel, aluminum, and other common base materials. Its Grade 9 rating places it above the common Grade 5 and Grade 8 classifications, making it appropriate for high-load or high-vibration installations where fastener integrity is critical.

Key Features

• Grade 9 alloy steel construction for high tensile and proof-load strength
• 5/16-18 UNC coarse thread for fast engagement and broad compatibility
• 4-inch length under head accommodates thicker joint stacks
• Partial threading concentrates clamping force at the joint
• Zinc-plated clear chromate finish provides baseline corrosion resistance
• Inch-series dimensions per standard UNSPSC 31161501 fastener classification

Compatibility

Designed as a standard inch-series hex head cap screw for use in any application requiring a 5/16-18 thread and a 4-inch grip length in alloy steel construction.

Installation Notes

Install using a standard hex wrench or socket driver sized for a 5/16-18 cap screw head. Torque to the value specified by the equipment manufacturer or applicable structural standard for Grade 9 alloy steel fasteners. Ensure mating threads and bearing surfaces are clean and free of debris before installation. Follow all applicable codes and manufacturer guidelines for the assembly being serviced.