Holo-krome 73145 Hex Socket Cap Screw 1/2-20 Unf

Product Description

The HOLO-KROME 73145 is a partially threaded hex socket cap screw intended for high-strength fastening applications in mechanical assemblies, industrial equipment, and precision fabrication work. It features a 1/2-20 UNF thread size and measures 3.5 inches in length under the head. The drive is a 3/8-inch internal hex socket, requiring a standard hex key or Allen driver. Constructed from alloy steel with a black oxide coating, this fastener delivers solid corrosion resistance and surface hardness suited for demanding service environments. Machinists, millwrights, and maintenance technicians typically install this type of fastener.

This screw is suited for use in mechanical assemblies where fine-thread engagement and high tensile strength are required. The 1/2-20 UNF thread pitch provides finer thread engagement compared to coarse-thread equivalents, making it appropriate for applications where vibration resistance or precise clamping load is critical. It is partially threaded, which concentrates clamping force at the bearing surfaces of the joint. Typical applications include machine frames, tool fixtures, motor mounts, and industrial equipment assembly where reliable metal-to-metal fastening is needed.

Key Features

• 1/2-20 UNF fine-thread profile for enhanced vibration resistance and precise torque control
• 3.5-inch length under head accommodates thicker joint stacks
• Partial threading concentrates clamping force between joined surfaces
• Alloy steel construction provides high tensile and shear strength
• Black oxide finish adds corrosion resistance and reduces light reflection in precision environments
• Conforms to ASME B18.3 and ASTM A574 fastener standards

Compatibility

Designed as a standard ASME B18.3 hex socket cap screw for use in any application requiring a 1/2-20 UNF partially threaded fastener with a 3/8-inch internal hex drive.

Installation Notes

Installation should be performed by a qualified machinist, millwright, or maintenance technician using a properly sized 3/8-inch hex key or socket driver. De-energize and lock out all equipment before fastener replacement or torquing operations. Thread engagement should be confirmed before applying final clamping load to avoid cross-threading the fine UNF thread. Follow applicable equipment manufacturer specifications for torque values and joint design requirements.