Tube-Alloy 242-O description: Tube-Alloy 242-O is a self-shielded, flux-cored wire that deposits a premium martensitic alloy steel. It has excellent resistance to adhesive (metal-to-metal) wear. The deposit’s good resistance to abrasion and impact makes it a versatile overlay alloy. It is designed for use as an overlay on carbon and low-alloy steels or a base of Tube-Alloy Build Up-O. With proper preheating, crack-free deposits can be obtained. Tube-Alloy 242-O should never be used for joining. Similar to AWS A5.21, classification ERC Fe-2.