Holo-krome 720003984 Hex Socket Cap Screw 1-8 Unc

Product Description

The HOLO-KROME 720003984 is a heavy-duty hex socket cap screw designed for high-load mechanical fastening applications. It features a 1-8 UNC thread and a 10-inch length under head, making it suited for through-bolting thick assemblies, structural joints, and industrial equipment. The screw is partially threaded, which helps maintain clamping force across the unthreaded shank. Manufactured from alloy steel and finished with a black oxide coating, it delivers solid corrosion resistance for indoor and controlled-environment use. The 3/4-inch hex drive socket accepts a standard hex key or socket driver. This fastener meets ASME B18.3 and ASTM A574 standards, confirming its mechanical strength for critical applications. Licensed machinists, millwrights, and industrial maintenance technicians are the typical installers.

This screw is appropriate for medium to heavy industrial assemblies where a countersunk or flush-head socket fastener is required. The 1-8 UNC coarse thread makes it compatible with tapped holes in steel plates, machine bases, jigs, fixtures, and structural frames. Partial threading is standard practice for fasteners at this length to prevent galling and to allow the shank to bear shear loads independently of the thread engagement. The black oxide finish reduces surface reflectivity and provides light rust inhibition in dry or lightly oiled environments.

Key Features

• 1-8 UNC coarse thread for robust engagement in steel and alloy tapped holes
• 10-inch length under head accommodates thick stack assemblies and long through-bolt applications
• Partially threaded shank distributes shear loads away from the threaded section
• Alloy steel construction meets ASTM A574 mechanical strength requirements
• Black oxide finish provides light corrosion protection and low surface reflectivity
• 3/4-inch hex socket drive compatible with standard hex keys and socket drivers
• Conforms to ASME B18.3 dimensional standards

Compatibility

Designed as an OEM-style replacement or standard-service hex socket cap screw for industrial machinery, structural assemblies, and fabrication applications requiring a 1-8 UNC partially threaded fastener.

Installation Notes

Installation should be performed by a qualified millwright, machinist, or maintenance technician familiar with torque requirements for alloy steel socket cap screws at this thread size. Ensure the mating tapped hole is clean and free of debris before installation. Use a properly sized 3/4-inch hex key or socket driver to avoid cam-out and fastener damage. Apply a thread lubricant or anti-seize compound as appropriate for the operating environment to prevent galling during installation and future removal.