Oerlikon Inertrod 309LMo description: INERTROD 309LMo is a W 23 12 2 L/ER 309L Mo (similar) type solid TIG welding rod depositing a low C-22Cr 12Ni 2.5Mo weld metal. Suitable for use mainly with Ar shielding gas. INERTROD 309LMo is used for the welding of stainless steels to mild and medium tensile steels. Used for intermediate layers on structural steel prior to depositing 316L grade stainless steel cladding. Also used for buffer layers prior to surfacing, when Mo is a required alloying element. The weld metal has a delta-ferrite content of 15% resulting in good resistance to hot cracking.