Esab 598739 Mig Welding Nozzle 1/2 Inch Bore ST-16 ST-21

Product Description

The ESAB 598739 is a No. 8 MIG welding nozzle with a 1/2-inch bore diameter, designed for use with ESAB ST-16, ST-21, and ST-21M MIG welding guns. The nozzle channels shielding gas around the arc to protect the weld pool from atmospheric contamination. Proper nozzle selection and condition directly affect gas coverage, spatter buildup, and overall weld quality. This is a consumable replacement part installed and serviced by welders and welding technicians performing MIG and wire-feed welding operations in fabrication, maintenance, and repair environments.

This nozzle is suited for MIG welding applications where consistent shielding gas coverage is required. The 1/2-inch bore accommodates standard wire and contact tip clearances used in light to medium-duty welding work. It is a direct replacement consumable for the ST-16, ST-21, and ST-21M gun platforms. Welders working in both shop and field environments will find this nozzle appropriate for general-purpose wire-feed welding on ferrous and non-ferrous base metals.

Key Features

• 1/2-inch bore diameter for standard shielding gas flow coverage
• No. 8 nozzle sizing for use on ST-16, ST-21, and ST-21M MIG guns
• Consumable design for quick field replacement during gun maintenance
• Sold individually as a single unit replacement

Compatibility

Compatible with ESAB ST-16, ST-21, and ST-21M MIG welding guns as stated by the manufacturer.

Installation Notes

Installation is performed by the welding operator or welding technician. Before replacing the nozzle, shut off the wire feeder and shielding gas supply, and allow the gun to cool completely. Thread or press the nozzle onto the gun diffuser according to the gun manufacturer's instructions. Inspect the contact tip and diffuser for spatter buildup and replace as needed during the same service interval.

Technical Specifications

• Bore Diameter: 1/2 inch
• Nozzle Size: No. 8
• Length: 1.3 inches
• Width: 3.65 inches
• Height: 5.9 inches
• Weight: 0.26 pounds
• Unit of Measure: Each

Standard Information

• Brand: ESAB
• Manufacturer Part Number: 598739