Impact Socket Wrench PRO Cylinder 66370 (21) — PRO brand, model 66370, 21 mm

PRO Cylinder impact socket wrench model 66370 (21) is a 21 mm impact socket designed for use with pneumatic or electric impact wrenches. It fits standard 1/2" drive impact tools and is built for repeated heavy-duty use in automotive maintenance, tyre service and industrial repair environments. The socket's cylinder form factor and 21 mm opening provide secure engagement with hexagonal nuts and bolts while allowing access in confined spaces typical of wheel hubs and machinery assemblies.

Advantages

The socket is manufactured from impact-rated alloy steel to resist deformation under high torque and repeated shocks from impact tools. Heat-treated construction and a corrosion-resistant finish increase service life and maintain reliable fitment. Its precise 21 mm internal profile reduces rounding of fasteners and ensures consistent torque transfer from pneumatic or electric impact wrenches. The 1/2" drive interface is compatible with common impact tool sizes used in professional workshops.

Suitable for

• Automotive wheel nut removal and installation
• Tire service and brake maintenance
• General mechanical assembly and disassembly under high torque
• Industrial equipment repair and maintenance

Key specifications

• Socket size: 21 mm
• Drive type: 1/2" drive compatible with impact tools
• Design: cylinder (deep/recessed profile for access)
• Material: impact-rated alloy steel with heat treatment
• Finish: corrosion-resistant surface treatment
• Intended use: compatible with pneumatic and electric impact wrenches

How to use

Select the 21 mm PRO Cylinder impact socket and attach it securely to a 1/2" drive impact wrench. Position the socket squarely over the fastener and apply short bursts of the impact wrench while maintaining steady hand control. For loosening, start at lower torque settings if available and increase as needed; for tightening, follow torque specifications for the fastener using an appropriate torque-control method after initial engagement with the impact tool. Inspect the socket for wear or damage regularly and replace if deformation or cracking is visible.

Usage recommendations

Use appropriate personal protective equipment, including eye and hearing protection, when operating impact wrenches. Avoid using the socket with manual ratchets or extensions not rated for impact use. Store in a dry place to minimise corrosion and keep a matched set of impact-rated sockets to ensure proper fit and safe operation.