Oerlikon Inertrod 309L description: INERTROD 309L is a W 23 12 L/ER 309L type solid TIG welding rod depositing a low C-23Cr 12Ni weld metal. Suitable for use mainly with Ar shielding gas. INERTROD 309L is used for the welding of stainless steels to mild and medium tensile steels. It is ideal for depositing intermediate layers on structural steel prior to depositing 308 grade stainless steel. Also used for the welding of clad steels where service temperatures <300C. The weld metal has a delta-ferrite content of 12% resulting in good resistance to hot cracking. TIG rod for welding dissimilar steels and for use with undercoats for facings. Good mechanical strengths and resistance to hot oxidation.