Oerlikon Carborod 1A description: CARBOROD 1A is a copper coated W4Si1/ER70S-6 type solid TIG welding rod depositing a C-1.5Mn weld metal. Suitable for use mainly with Ar shielding gas. CARBOROD 1A is used for the welding of mild and C-Mn steels, requiring a yield strength <460MPa, with impact toughness properties down to -40C. Increased levels of manganese and silicon scavenge oxides and promote weld pool fluidity resulting in a superior weld bead appearance with an even contour finish.