Bowmalloy BOW36458 Hex Head Cap Screw 5/8-18 X 4-1/2 in Grade 9

Product Description

The BOWMALLOY BOW36458 is a Grade 9 steel hex head cap screw with a 5/8-18 thread size and a 4-1/2 inch length under head. It features partial threading and a Bowma-Guard zinc-plated clear chromate finish for corrosion resistance. This fastener is suited for high-strength bolted connections in structural, mechanical, and industrial applications. Tradespeople including millwrights, pipefitters, ironworkers, and mechanical contractors install this type of hardware where torque-critical, high-load fastening is required. The unified fine thread (UNF) pitch of 5/8-18 provides increased thread engagement and clamp load compared to coarse thread equivalents.

This cap screw is appropriate for use in industrial machinery assemblies, structural steel connections, heavy equipment maintenance, and mechanical systems requiring Grade 9 high-strength fasteners. The partial threading design allows for greater shank bearing area in bolted joint assemblies. It is sold in packages of 25, making it suitable for both single-unit repairs and small-batch assembly operations in shop or field settings.

Key Features

• Grade 9 steel construction for high-strength bolted joint applications
• 5/8-18 unified fine thread (UNF) for increased clamp load and thread engagement
• 4-1/2 inch length under head with partial threading for shank bearing area
• Bowma-Guard zinc-plated clear chromate finish for corrosion protection
• Inch measurement system; UNSPSC Code 31161501
• Packaged in quantities of 25 per unit

Compatibility

Designed as a standard inch-series Grade 9 hex head cap screw for use in high-strength mechanical and structural bolted connections where 5/8-18 UNF thread pattern and 4-1/2 inch under-head length are specified.

Installation Notes

Installation should be performed by a qualified mechanic, millwright, or tradesperson familiar with high-strength fastener torque requirements per applicable standards such as ASME or OEM specifications. Always power down and de-energize or depressurize associated equipment before fastener removal or replacement. Use a calibrated torque wrench to achieve the specified clamp load; do not estimate torque by feel on Grade 9 hardware. Inspect mating threads and seating surfaces for damage before installation.