Bowmalloy 36301 Hex Head Cap Screw 1/4-28 X 5/8 in Grade 9

Product Description

The BOWMALLOY 36301 is a fully threaded hex head cap screw engineered for high-strength fastening applications. Built from Grade 9 alloy steel with a clear zinc chromate finish, this fastener delivers superior tensile strength over standard Grade 5 and Grade 8 hardware while providing corrosion resistance in moderate-exposure environments. Sized at 1/4-28 x 5/8 inches, it uses a unified fine thread pitch suited to precision assemblies where vibration resistance and tight thread engagement are critical. Mechanics, millwrights, and maintenance technicians specify Grade 9 hardware when standard alloy grades fall short of load requirements.

This cap screw is appropriate for general industrial, mechanical, and equipment assembly applications where fine-thread, high-strength fasteners are specified. The 1/4-28 fine thread series is common in automotive, HVAC equipment frames, pump housings, and precision machinery. The 5/8-inch length under head suits thinner structural members and brackets where a longer fastener would bottom out or over-penetrate. The clear zinc chromate plating is compatible with standard indoor and lightly protected outdoor service conditions.

Key Features

• Grade 9 alloy steel construction for elevated tensile and proof load ratings above Grade 8
• 1/4-28 unified fine thread for improved vibration resistance and precise torque control
• Fully threaded shank along the 5/8-inch body length for maximum thread engagement in thin material
• Clear zinc chromate finish provides baseline corrosion protection and a clean appearance
• Inch measurement system, UNSPSC Code 31161501 for procurement and catalog alignment

Compatibility

Designed as an OEM-style and aftermarket replacement hex head cap screw for any application specifying a 1/4-28 x 5/8-inch fully threaded Grade 9 alloy steel fastener with clear zinc chromate finish.

Installation Notes

Installation should be performed by qualified mechanical or maintenance technicians following applicable equipment manufacturer torque specifications for Grade 9 fine-thread fasteners. De-energize and lock out all equipment before fastener service to comply with OSHA lockout-tagout requirements. Use a properly sized hex wrench or socket to avoid rounding the hex head. Do not substitute this fastener in applications requiring a coarse-thread or metric-threaded fastener without verifying thread compatibility.