4391 - Bernard Style 4391 Brass MIG Nozzle, 5/8 Inch, 300A

Product Overview

The Bernard Style 4391 Nozzle is a premium aftermarket replacement component designed for heavy-duty MIG welding applications. Engineered to meet the rigorous demands of industrial environments, this nozzle is constructed from high-grade brass, offering excellent thermal conductivity and resistance to mechanical wear. It is specifically rated for operation up to 300 Amps, making it suitable for a wide range of medium to heavy fabrication tasks.

Technical Specifications & Compatibility

This nozzle features a 5/8-inch (15.9 mm) bore orifice, which provides a balanced shielding gas envelope ideal for standard welding wires and transfer modes. A critical specification for this component is its compatibility: it is designed exclusively to fit the 4335 gas diffuser. The one-piece nozzle and insulator assembly design simplifies consumable changeovers and reduces the risk of insulator failure during operation. Users should verify their MIG gun setup includes the 4335 diffuser to ensure proper fitment and safety.

Application & Performance

In professional welding setups, the nozzle plays a pivotal role in directing shielding gas over the weld pool to prevent porosity and oxidation. The brass material of the 4391 style nozzle effectively dissipates heat, prolonging the service life of the front-end consumables. Whether used in manufacturing, automotive repair, or structural steelwork, this nozzle delivers consistent performance and reliability, mirroring the specifications of the original manufacturer's part number 4391.