Holo-krome 720001177 Hex Socket Cap Screw 1/4-20 Unc

Product Description

The HOLO-KROME 720001177 is a partially threaded hex socket cap screw designed for high-strength fastening applications in industrial, mechanical, and trade assembly work. It features a 1/4-20 UNC thread size and a 4.5-inch length under head, giving it substantial grip in deeper through-hole or tapped applications. The 3/16-inch hex drive socket accepts a standard Allen key or hex bit driver. Constructed from alloy steel with a black oxide coating, this screw offers good corrosion resistance for indoor and light-duty protected environments. Machinists, millwrights, and mechanical contractors rely on this fastener class for precise, high-torque installations where a standard Phillips or slotted head is not appropriate.

This screw is suited for use in equipment assembly, machinery maintenance, and fabrication environments where a recessed drive and high tensile strength are required. The partial threading allows the unthreaded shank to bear shear loads, making it appropriate for applications where precise alignment or shear resistance between mated components is a priority. It is commonly installed in metal-to-metal fastening scenarios across HVAC equipment frames, electrical panel assemblies, pump housings, and general mechanical fixtures.

Key Features

• 1/4-20 UNC thread for compatibility with standard inch-series tapped holes
• 4.5-inch length under head provides deep engagement in thick or stacked assemblies
• Partially threaded shank supports shear load applications
• 3/16-inch hex socket drive accepts standard Allen keys and hex bit drivers
• Alloy steel construction meets ASME B18.3 and ASTM A574 standards for high tensile strength
• Black oxide finish provides moderate corrosion resistance in dry or protected environments

Compatibility

Designed as an OEM-style replacement or direct-fit fastener for any application requiring a 1/4-20 UNC partially threaded hex socket cap screw with a 4.5-inch length under head, conforming to ASME B18.3 and ASTM A574 standards.

Installation Notes

Installation is performed using a 3/16-inch hex key or hex bit driver. Verify that the receiving tapped hole is clean and free of debris before driving the fastener. Follow applicable mechanical and structural codes for torque requirements based on joint material and application. Avoid overtightening, which can strip threads in softer base materials or induce stress fractures in the fastener shank.