Value Collection 121091PR Set Screw 1/4-20 Grade 8

Product Description

The VALUE COLLECTION 121091PR is a Grade 8 alloy steel set screw with a cone point tip and a 1/4-20 UNC thread. The screw measures 1/4 inch in overall length and is driven by a 1/8-inch hex key. Cone point set screws are designed to apply concentrated, permanent-style clamping force against a shaft or mating surface, making them well suited for applications requiring high holding power. This fastener meets ASME/ANSI B18.3 and ASTM F912 dimensional and material standards. Installation is performed by licensed mechanics, millwrights, or equipment technicians working on rotating assemblies and mechanical components.

This set screw is used in light industrial and commercial mechanical assemblies where a compact, flush-seating fastener is needed to secure a hub, collar, pulley, or gear to a shaft. The cone point geometry allows the tip to bite into the shaft surface, providing strong axial and rotational resistance. The 1/4-20 UNC thread is one of the most common thread sizes in North American mechanical hardware, making this screw a standard replacement or new-build fastener across a broad range of equipment types.

Key Features

• Cone point tip delivers concentrated contact force for high holding power on shaft assemblies
• Grade 8 alloy steel construction provides high tensile and torsional strength
• 1/4-20 UNC thread is a widely used standard size for easy sourcing and replacement
• 1/8-inch hex drive accepts standard hex keys and L-wrenches
• Meets ASME/ANSI B18.3 and ASTM F912 standards for dimensional accuracy and material properties
• Compact 1/4-inch overall length for installations with limited clearance

Compatibility

Designed as a standard 1/4-20 UNC cone point set screw for use in mechanical assemblies requiring ASME/ANSI B18.3 and ASTM F912 compliant fasteners.

Installation Notes

Set screws of this type are installed by mechanics, millwrights, or qualified technicians using a 1/8-inch hex key or L-wrench. Always de-energize and lock out rotating equipment before installing or removing set screws from shaft assemblies. Ensure the shaft surface and thread engagement are clean and free of debris before tightening. Do not exceed the rated torque capacity of the alloy steel material for the thread size.