Bowmalloy 36066 Hex Head Cap Screw 3/8-16x4 in Grade 9

Product Description

The BOWMALLOY 36066 is a Grade 9 alloy steel hex head cap screw designed for high-strength fastening applications in industrial, mechanical, and structural assemblies. It measures 3/8-16 thread size with a 4-inch length under the head and features partial threading for secure clamping in bolted joint applications. The zinc-plated clear chromate finish provides corrosion resistance in moderately harsh environments. This fastener is sized for standard 3/8-inch hex tooling and is sold in packages of 25 units, making it suitable for job-lot procurement by mechanical contractors, millwrights, and industrial maintenance technicians.

Grade 9 alloy steel cap screws are commonly used in heavy equipment assemblies, structural brackets, machinery frames, and agricultural or construction equipment where higher proof load and tensile strength than Grade 5 or Grade 8 fasteners are required. Partial threading allows the unthreaded shank to bear shear loads, making this screw well suited for bolted joints with close-tolerance clearance holes. Trade installers specify this fastener where torque requirements and clamping force demand a high-grade inch-series hex bolt.

Key Features

• Grade 9 alloy steel construction for high tensile and proof load ratings
• 3/8-16 UNC thread form in inch measurement system
• 4-inch length under head for deep-reach or stacked-material applications
• Partial threading to support shear load on the unthreaded shank
• Zinc-plated clear chromate finish for moderate corrosion resistance
• Packaged in quantities of 25 to support job-lot and service-truck stocking

Compatibility

Designed as an OEM-style replacement or service fastener for equipment and assemblies requiring 3/8-16 inch-series hex head cap screws with Grade 9 alloy steel strength ratings.

Installation Notes

Installation of high-strength cap screws should be performed by qualified mechanical or industrial maintenance technicians familiar with proper torque procedures for Grade 9 inch-series fasteners. Always use a calibrated torque wrench and consult the equipment manufacturer's torque specification table for the applicable joint class. De-energize and lock out all equipment before fastener removal or installation per applicable OSHA lockout/tagout requirements. Do not substitute a lower-grade fastener in any application specified for Grade 9.