A program was conducted to evaluate the effects of a proprietary backup fluxwelding technique on the impact fracture toughness properties of Ti-5Al-2.5 Sn alloy plate. Precracked Charpy often called subsize Charpy specimens were tested under impact loads at -320, -100, room temperature, and 550 F. The weld and heat affected zone HAZ had greater fracture toughness resistance than the base metal. The fracture resistance work per unit area WA decreased with decreasing test temperature. At -320 F the weld and HAZ retained 13 of their fracture resistance at room temperature. However, the weld- and HAZ-converted WA impact fracture resistance at -320 F had a K sub c about 125 ksi square root inch which indicated good toughness for this temperature. The fracture resistance did not appear to be a function of the specimens location through the thickness of the plate for a given specimen orientation. In general, the fracture resistance of the weld and HAZ compared to the base metal was excellent.