Southwire 339M Insulated Grounding Bushing 3.5 Inches

Product Description

The SOUTHWIRE 339M is a 3.5-inch malleable iron insulated grounding bushing designed for use in electrical conduit installations. This fitting threads onto the end of rigid metal conduit or intermediate metal conduit to provide a smooth, insulated throat that protects conductor insulation from abrasion at entry points. It also provides a grounding lug or bonding connection point, making it a code-required component in many service entrance and feeder conduit terminations. Electricians rely on this bushing to meet NEC bonding requirements at enclosure knockouts where conduit terminates.

This bushing is suited for commercial and industrial electrical installations where 3.5-inch rigid or IMC conduit terminates at panelboards, switchgear, junction boxes, and service entrance enclosures. It is a standard component in new construction wiring, service upgrades, and conduit retrofit work requiring proper bonding continuity at conduit terminations.

Key Features

• 3.5-inch trade size fits standard rigid metal conduit and IMC terminations
• Malleable iron construction for durability in demanding installation environments
• Insulated throat protects conductor insulation from conduit edge damage
• Grounding and bonding connection point supports NEC compliance at conduit terminations
• Threaded design for secure, tool-tightened connection to conduit end threads

Compatibility

Designed as an OEM-style fitting for 3.5-inch rigid metal conduit and intermediate metal conduit terminations in commercial and industrial electrical systems.

Installation Notes

Installation should be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and applicable local codes. De-energize and lock out the circuit or service before working at any enclosure or panelboard where this bushing will be installed. Thread the bushing securely onto the conduit end using appropriate conduit wrenches, then connect the bonding jumper or grounding conductor to the lug as required. Do not overtighten in a way that cracks the insulated throat.

Technical Specifications

• Trade Size: 3.5 inches
• Material: Malleable Iron
• Weight: 20 pounds
• UPC: 75133813430

Standard Information

• Brand: SOUTHWIRE
• Manufacturer Part Number: 339M