Difference between 000 and 000L Stainless Steel Difference between Stainless Steel 000 and 000L.000L stainless steel is an extra-low carbon version of the 000 steel alloy.The difference between 000 and 000L stainless steel is that 000L has a 0.00 max carbon and is good for welding whereas 000 has a mid rangeASTM Type Si, Cr N, Notes ASTM A000/A000M 0.00 00.0-00.0 0.00 Stainless Steel Plate,Sheet,