What filler rods to us to weld 4140 material?

When welding 4140 steel, it's common to use filler rods that are compatible with high-strength low-alloy steels. Typically, ER80S-D2 or ER70S-6 filler wires are recommended for MIG welding, while E8018-C3 rods are suitable for TIG and stick welding. These filler materials help maintain the mechanical properties of the welded joint and ensure good fusion with the 4140 base material. Always consider preheating and post-weld heat treatment to reduce the risk of cracking.