Gearwrench 84579N Impact Socket 1/2 in Drive 21mm

Product Description

The GEARWRENCH 84579N is a 6-point hex drive impact socket designed for heavy-duty fastener work in professional and industrial applications. Built from chromium-molybdenum steel with a black oxide finish, it is engineered to absorb and transfer the high-torque output of pneumatic and electric impact drivers without fracturing or deforming. The 1/2 inch drive accepts standard 1/2 inch impact wrenches, and the 21mm socket size covers a wide range of metric fasteners common in automotive, fleet, and mechanical maintenance work. High-visibility laser-etched markings allow fast size identification in low-light or high-volume shop conditions.

This socket is suited for automotive repair, fleet maintenance, equipment service, and general mechanical work where metric fasteners are standard. The off-corner loading design reduces contact stress on fastener flats, minimizing the risk of rounding during removal of stubborn or corroded hardware. Secondary hard-stamped size markings provide a permanent backup to the laser etching, supporting long-term durability in demanding shop environments. Licensed mechanics, fleet technicians, and experienced DIYers working with impact tools will find this a direct-fit addition to a standard 1/2 inch drive impact set.

Key Features

• Chromium-molybdenum steel construction rated for impact tool use
• Black oxide finish resists corrosion and reduces glare
• 6-point hex drive geometry maximizes contact with fastener flats
• Off-corner loading design reduces fastener rounding during high-torque removal
• High-visibility laser-etched markings for fast size identification
• Secondary hard-stamped size markings for permanent, wear-resistant labeling
• Meets ASME B107.33M standards

Compatibility

Designed for use with standard 1/2 inch drive impact wrenches and ratchets. Fits 21mm metric fasteners. Compatible with pneumatic, cordless, and corded electric 1/2 inch impact drivers.

Installation Notes

Install and remove using standard 1/2 inch drive impact tools. Ensure the socket is fully seated on the drive anvil and the fastener before applying torque. Do not use impact sockets on non-impact hand ratchets in applications that exceed the tool rating. Inspect the socket for cracks or deformation before each use and remove from service if damage is found.