UTP A 63 description: UTP A 63 is suitable for particularly crack resistant joining and surfacing of high-strength ferritic and austenitic steels, hard manganese steels and cold-tough steels, as cushioning layer under hard alloys, dissimilar metal joints. The weld metal of UTP A 63 is scale resistant up to 850° C, cold-tough to–110°C. Work hardening. Hardness of the pure weld metal: approx. 200 HB.