Knipex 4421J21 Internal Retaining Ring Pliers Bent Nose

Product Description

The KNIPEX 4421J21 is a bent-nose internal retaining ring plier designed for installing and removing internal snap rings in bores and housings. Built with a 90-degree tip angle and a 1.80 mm tip diameter, this tool provides precise engagement with ring eyelets in confined or perpendicular access points. The overall length of 6-3/4 inches gives the technician adequate leverage without excessive reach. The body is forged steel and oil-hardened for durability under repeated use. Non-slip plastic handles provide a secure grip during controlled insertion and extraction. This tool is used by mechanics, millwrights, and industrial maintenance technicians working on assemblies with internal retaining rings.

This plier is suited for internal retaining ring service in motors, gearboxes, hydraulic cylinders, pumps, and similar assemblies where rings are seated inside a bore. The bent-nose configuration is selected when straight-on access is not practical, such as when working at an angle to the bore axis or in partially obstructed housings. It is a standard tool in HVAC compressor service, pump rebuilds, and general mechanical assembly work requiring ring retention in blind or angled bores.

Key Features

• 90-degree bent nose tip for angled or obstructed bore access
• 1.80 mm tip diameter for precise ring eyelet engagement
• Forged steel body, oil-hardened for long service life
• Non-slip plastic handles for controlled grip
• 6-3/4 inch overall length for adequate leverage
• Meets DIN 5256 D standard

Compatibility

Designed for use with internal retaining rings sized to accept a 1.80 mm tip diameter; verify ring eyelet size against tip diameter before use to confirm fitment.

Installation Notes

Disconnect and de-energize any equipment before servicing assemblies that contain retaining rings. Compress the ring tips only enough to seat in the ring eyelets to avoid tip slippage or ring deformation. Eye protection is required when installing or removing snap rings due to the potential for ring ejection under spring load. This tool should be used only for internal retaining rings; do not use on external rings or as a general-purpose plier.