S305408-019 - Hobart HB-28 ER70S-6 .035" MIG Welding Wire - 2lb Spool

Technical Overview: Hobart HB-28 ER70S-6 Solid MIG Wire

The Hobart HB-28 is a premium-grade, copper-coated mild steel solid wire designed for Gas Metal Arc Welding (GMAW) applications. Conforming to AWS A5.18 ER70S-6 classification, this wire is formulated with elevated levels of manganese and silicon deoxidizers. These chemical additions are essential for scavenging oxygen from the weld pool, thereby significantly reducing the formation of porosity and other defects when welding on base metals that exhibit light to moderate amounts of rust, mill scale, or oil. This makes the HB-28 a robust choice for maintenance and repair operations where surface preparation cannot always be perfect.

With a diameter of 0.035 inches (0.9 mm), this wire is highly versatile, offering an optimal balance between deposition rate and heat input control. It is particularly well-suited for short-circuit transfer modes, allowing for effective welding of thin-gauge sheet metal without burn-through, while also being capable of spray transfer at higher parameters. The copper coating applied to the wire surface serves multiple technical functions: it enhances electrical conductivity at the contact tip for consistent arc initiation, reduces friction within the liner and gun to promote smooth feedability, and protects the wire from oxidation during storage.

The HB-28 demonstrates excellent compatibility with various shielding gases. When used with 100% Carbon Dioxide (CO2), it provides deep penetration and cost-effective operation, suitable for structural steel work. Alternatively, utilizing a mixture of 75% Argon and 25% CO2 (C25) yields a smoother arc, reduced spatter levels, and a flatter bead profile with improved wetting action at the toes of the weld. This wetting characteristic is crucial for ensuring uniform tie-in and minimizing stress concentrations. The 2-pound spool configuration is dimensionally compatible with a wide range of portable MIG welding power sources and spool guns, making it an ideal solution for field applications and small-scale fabrication tasks requiring high-strength, reliable joints.