Steel, branded as EXEM, is treated with calcium during process to improve its machining properties.
It enables increase of machining speeds and reduces tool wear.
Production of the spring steel requires addition of some substances (silicon, chromium, vanadium) and removal of another (hydrogen).
Properties of such steel are elasticity, ability for plastic work and durable dynamic strength.
Forging steel must have special properties, required by final product and also ability for plastic work, because products from modern forge shops are of complex shapes.