Proto J7221M Impact Socket 3/8 in Drive 21mm 6-pt

Product Description

The PROTO J7221M is a 6-point impact socket designed for high-torque fastener work in demanding trade environments. It accepts a 3/8 inch drive and fits 21mm fasteners, with an overall length of 1-3/32 inches. The 6-point contact geometry reduces fastener rounding under heavy impact loads compared to 12-point designs. Built for use with impact wrenches and drivers, this socket is suited for automotive service, mechanical contracting, and industrial maintenance applications where consistent torque delivery and socket durability are required.

This socket is appropriate for residential and commercial mechanical work where a 3/8 inch drive impact tool is the preferred driver. Typical applications include suspension and drivetrain fasteners, equipment assembly, and general mechanical service where a 21mm hex-drive socket is specified. The compact 1-3/32 inch overall length suits confined-space installations where a longer socket would interfere with surrounding components.

Key Features

• 3/8 inch drive size compatible with standard impact wrenches and ratchets
• 21mm socket size for metric fastener applications
• 6-point hex drive geometry minimizes fastener rounding under impact loads
• Overall length of 1-3/32 inches suits tight-clearance work areas
• Single-piece construction rated for impact tool use

Compatibility

Designed as a replacement-style impact socket for use with 3/8 inch drive impact wrenches, air ratchets, and hand ratchets accepting standard 3/8 inch drive tooling.

Installation Notes

Install and remove using a 3/8 inch drive impact wrench or ratchet rated for the fastener torque requirement of the application. Confirm the socket is fully seated on the fastener before applying torque to prevent slippage. Always de-energize or depressurize equipment before servicing fastened assemblies. Inspect the socket for cracks or deformation before each use and remove from service if damage is found.