RXR is an E70T-1 wire that has a higher level of de-oxidizing elements to handle mill scale, rust and other contaminants
Hobart® Fabco® RXR S246529-008 Carbon Steel Welding Wire, Gas Shielded, Diameter: 3/32 Inch, Current Type: DC+, Package: 600 lb Drum, AWS Class: AWS A5.20: E70T-1C, E70T-9C, AWS A5.20M: E490T-1C, E490T-9C, Tensile Strength: 86000 psi, Yield Strength: 75000 psi, Elongation in 2" (%): 26% (As Welded), Charpy V-Notch: 28 ft.-lb. At -20 deg F, Welding Process: MIG (GMAW And SAW), Weld Metal Composition: 0.07% Carbon (C), 1.66% Manganese (Mn), 0.64% Silicon (Si), 0.012% Phosphorus (P), 0.009% Sulphur (S), Applicable Materials: Structural Steel