Abstract: A process for obtaining a plate of zirconium alloy comprising at least one portion of excess thickness of at least 0.5 mm relative to a large adjacent face, the portion having edges with angles equal to 90.degree. to 105.degree. and flanks which are connected without depressions to the large adjacent faces. According to the process, a surface portion of a blank plate located straight above a desired portion of excess thickness is coated with a continuous coating which is resistant to a pickling composition to be used, the coated portion widened beyond the desired portion of excess thickness by 0.5-1.5 times the amount of the excess thickness. The coated blank plate is immersed a plurality of times, without passage of electric current, in a pickling bath comprising HF, an oxidizing agent and water, and having a dissolved Zr content less than 12 g/l and a temperature below 35.degree. C. Each immersion removes less than 0.3 mm of thickness over the portions of the blank plate which are not coated.