Bowmalloy 36391 Hex Head Cap Screw 7/16-20 X 4 in Grade 9

Product Description

The BOWMALLOY 36391 is a Grade 9 alloy steel hex head cap screw designed for high-strength fastening applications in industrial and mechanical assemblies. It measures 7/16-20 thread size at 4 inches in length under the head and features a clear zinc chromate finish for corrosion resistance. The partial threading provides a strong grip in applications where a defined clamp zone is required. This fastener is sized for use by mechanics, millwrights, and industrial maintenance technicians working on heavy-duty equipment where Grade 9 tensile strength is specified.

This cap screw is suited for industrial machinery, agricultural equipment, heavy transport, and structural fastening applications that require an inch-series, fine-thread fastener with elevated strength ratings. The 7/16-20 fine thread pitch provides precise torque control and greater thread engagement per inch compared to coarse thread configurations. It is typically installed wherever Grade 5 or Grade 8 fasteners are insufficient and a higher-strength alloy fastener is called for.

Key Features

• Grade 9 alloy steel construction for superior tensile and proof load strength
• Clear zinc chromate finish provides corrosion protection in demanding environments
• Partially threaded shank maintains a clean clamp zone for precision assemblies
• 7/16-20 fine thread pitch for controlled torque and strong thread engagement
• Inch measurement system for compatibility with standard SAE tooling

Compatibility

Designed as a high-strength inch-series replacement fastener for industrial, agricultural, and heavy equipment assemblies requiring a 7/16-20 fine thread, 4-inch hex head cap screw with Grade 9 alloy steel specification.

Installation Notes

Installation is performed by qualified mechanics or maintenance technicians using standard SAE hex tooling. Verify that mating threads are clean and undamaged before installation. Always torque to the specification required by the equipment manufacturer for Grade 9 fasteners. De-energize or lock out any equipment before removing or replacing structural fasteners.