Why choose steel?
Steel ensures high performance at really low weights. The new alloys, particularly Thermacrom, give a weight close to that of the aluminum alloys, together with a perfectly balancable elastic response, that is appreciated in particular on long traits. Unlike aluminum, steel is substantially stable over time, not requiring onerous maintenance cycles. If properly rust-treated, under normal conditions of use, it has almost unlimited fatigue resistance. It allows frames to be built with excellent performances, rigid yet comfortable, suitable for any type of use.

Steel is the material that was first used in the construction of top-of-the-range frames because of its superior mechanical characteristics, most notably its superior fatigue resistance and a breaking load second only to that of advanced composite materials. Columbus research has always worked towards the customization and development of materials with characteristics intended for cycling use. The results are of international importance. Columbus's history is the creation of steels with patented formulations such as the famous Nivacrom.

NIOBIUM
It's a special micro alloyed steel with Manganese, Chrome, Nickel, Molybdenum and Niobium. In the Columbus research and development tradition it can be considered the evolution from of the Thermacrom and Nivacrom alloy. It's designed to provide better mechanical properties and greater resistance to atmospheric corrosion than conventional carbon steels. For every top-of-the-line and competition frames where lightness and high reliability are fundamental. Like Vanadium in Thermacrom steel, Niobium increases yield strength by precipitation hardening and acts for refinement of grain size. Thanks to the special Columbus chemical composition, the combined effect of precipitation strengthening, and grain refinement the properties are incredibly increased inith respect. To standard steels. Niobium is a more effective strengthening agent than Vanadium. After mechanical deformation working and drawing, NIOBIUM undergoes a special heat treatment that gives the steel its final characteristics; this heat treatment is designed to minimize the tubes distortion and decarbonization phenomena. Columbus heat treatment results in a super fine high-strength microstructure of bainite, wich means high strength, hardness and long fatigue life.

Mechanical characteristics:
Ultimate tensile strength = 1050 ÷ 1250 MPa
Yeld strength: min 750 MPa
Minimum elongation: 14%

NIVACROM
The Nivacrom steel for the Zona series undergoes a series of processes and treatments, which, after drawing, homogenize the mechanical characteristics of the tube, making it uniform along the longitudinal axis. This makes the fatigue behaviour and weldability of the material excellent.

Mechanical characteristics:
Breaking load = 950÷1050 MPa
Elongation > 10%