Bowmalloy BOW36391 Hex Head Cap Screw 7/16-20 X 4 in Grade 9

Product Description

The BOWMALLOY BOW36391 is a Grade 9 steel hex head cap screw in a 7/16-20 thread size with a 4-inch length under the head. It features partial threading and a Bowma-Guard zinc-plated clear chromate finish that provides corrosion resistance in demanding service environments. This fastener is built to the inch measurement system and suits high-strength bolted connections where standard Grade 5 or Grade 8 hardware is insufficient. Licensed tradespeople working in heavy equipment, agricultural machinery, and industrial fabrication will find this screw appropriate for critical structural joints.

This screw is suited for applications requiring high-torque, high-tension fastening in metalwork assemblies. The partial thread configuration is well-suited for clamping through thick material where a full-thread engagement into a nut or tapped hole is not needed across the full grip length. Typical install scenarios include equipment frame assembly, bracket mounting, and structural steel connections in both shop fabrication and field repair contexts.

Key Features

• Grade 9 steel construction for high-strength bolted joint requirements exceeding Grade 8 specifications
• 7/16-20 unified fine thread (UNF) for tight thread pitch and strong clamp load retention
• 4-inch length under head accommodates thicker material stacks and long grip lengths
• Partial threading supports shear-critical joints and thick-material clamping applications
• Bowma-Guard zinc-plated clear chromate finish provides corrosion protection in exposed environments

Compatibility

Designed as a standard inch-series hex head cap screw compatible with 7/16-20 UNF nuts, washers, and tapped holes in steel assemblies requiring Grade 9 fastener strength.

Installation Notes

Installation should be performed by a qualified mechanic or fabricator familiar with proper fastener torque procedures for Grade 9 hardware. Always use a calibrated torque wrench and the appropriate hex socket or wrench to achieve the required clamp load without over-stressing the fastener. Inspect the mating threads for damage or contamination before assembly. Follow applicable equipment manufacturer specifications and relevant industry standards for fastener torque values and joint design.