Holo-krome 64088 Button Socket Cap Screw 5/8-11

Product Description

The HOLO-KROME 64088 is a button head socket cap screw designed for applications requiring a low-profile fastening solution with high clamping strength. It features a 5/8-11 UNC thread and a 1-1/2-inch length under head, fully threaded along the shank. The hex socket drive accepts a 3/8-inch hex key for installation and removal. Manufactured from alloy steel with a black oxide finish, this screw meets ANSI/ASME B18.3 and ASTM F835 standards and carries a Thread Fit Class of 3A. A hardness rating of 38 HRC provides reliable performance in demanding mechanical assemblies. Licensed tradespeople and maintenance technicians working on structural, industrial, or machinery applications will find this fastener suited to close-clearance installations where a standard hex head will not fit.

This screw is appropriate for use in general industrial, mechanical, and structural assemblies where a flush or low-profile fastener is needed. The button head profile distributes clamp load over a wider bearing surface compared to a standard socket head cap screw, making it well suited for sheet metal assemblies, guards, and enclosures. Right-hand thread direction follows standard convention. The black oxide finish offers mild corrosion resistance and reduces light reflection in field and shop environments.

Key Features

• 5/8-11 UNC thread with 3A fit class for consistent engagement and thread quality
• 1-1/2-inch length under head, fully threaded alloy steel shank
• 3/8-inch hex socket drive for standard hex key installation
• Button head profile with 1.0000-inch head diameter and 0.3310-inch head height for low-profile clearance
• 38 HRC hardness rating meets ASTM F835 mechanical requirements
• Black oxide finish for mild corrosion resistance and reduced reflectivity

Compatibility

Designed as a standard ANSI/ASME B18.3 button socket cap screw for use in mechanical assemblies, industrial equipment, and structural applications requiring a 5/8-11 UNC fully threaded low-profile fastener.

Installation Notes

Installation is performed with a 3/8-inch hex key or hex bit driver. Verify that mating threads are clean and free of debris before driving. Follow applicable torque guidelines from ASME or the equipment manufacturer for 5/8-inch alloy steel fasteners rated to 38 HRC. A licensed mechanic or qualified tradesperson should confirm proper thread engagement and pre-load for structural or load-bearing applications.