Abstract: The invention relates to the use of a chrome-nickel martensitic precipitation hardening stainless steel having the following composition: 10-14 mass % chromium, 7-11 mass % nickel, 0.5-6 mass % molybdenum, 0.5-4 mass % copper, 0.05-0.55 mass % aluminium, 0.4-1.4 mass % titanium, up to 0.3 mass % carbon+nitrogen, less than 0.05 mass % sulfur, less than 0.05 mass % phosphorus, up to 0.5 mass % manganese, up to 0.5 mass % silicium, up to 0.2 mass % tantalum, niobium, vanadium and tungsten, respectively, possibly 0.9 mass % cobalt, possibly 0.0001-0.1 mass % boron, the rest being iron and ordinary impurities. Said steel is used for producing surgery implants and osteosynthesis products which are pointwisely or long-lastingly used outside and inside a body.

Abstract: The aim of the invention is to produce mechanically driven rotary tools, preferably boring, milling, grinding and cutting tools which are stable, non-corrosive and biocompatible and also have high mechanical strength properties, in conjunction with good ductility properties. To this end, the invention relates to the use of a precipitation-hardenable, martensitic, stainless chromium-nickel steel having the following composition (in weight %): 10 to 14 of chromium; 7 to 11 nickel; 0.5 to 6 of molybdenum; 0.5 to 4 of copper; 0.05 to 0.55 of aluminium; 0.4 to 1.4 of titanium; up to 0.3 of carbon and nitrogen; less than 0.05 of sulphur; less than 0.05 of phosphorus; up to 0.5 of manganese; up to 0.5 of silicon; respectively up to 0.2 of tantalum, niobium, vanadium and wolfram; and optionally up to 9 of cobalt; optionally 0.0001 to 0.1 of boron; the reminder consisting of iron and common impurities.