Spring or harmonic steels
Technical data sheets for spring steels
Spring or harmonic steels are a particular category of construction steels and are characterized by a high elastic limit, with a chemical composition in which a high percentage of carbon and silicon is almost always present.These steels are used for making coil springs, stabilizer bars and elastic pliers for automatic machines. This category of steel is mostly used is 52SiCrNi5, which is often used for contructing tools such as augers and wrenches which undergo high stress.
The main characteristics of spring steel are to withstand an intermittent load, store energy and measure strengths.
General indications for spring or harmonic steel: it must have an elastic deformation with no plastic alteration, the unitary yield strength must therefore be high, a result which is obtained after appropriate hardening and tempering. Spring steel must have high hardenability that is verified by the jominy test, which can evaluate the core martensite that can be obtained. This must be at least 80%. To obtain greater elasticity and a high elastic limit, the steel must have a fine grain to make it less sensitive to overheating.