Oerlikon Carborod description: CARBOROD is a copper coated W2Si/ER70S-3 type solid TIG welding rod. Suitable for use mainly with Ar shielding gas. CARBOROD is suitable for welding mild and C-Mn steels, generally used for the root pass and to support welding when no back pass is possible. Excellent mechanical and toughness properties for low temperature applications, down to -40C. TIG rod for welding mild and carbon steels used in metal structures. For first passes and bottom chamfer as support passes or in cases where it is impossible to weld on the back.