What is Cold Working of Steel?
Cold working of steel refers to a set of metalworking processes carried out at room temperature, below the metal’s recrystallization point. These processes deform steel to achieve the desired shape, dimensions, and properties without heating it. The result is a material with improved mechanical properties such as higher strength and hardness, as well as enhanced surface finish and tighter dimensional tolerances. At Montanstahl, we specialize in cold rolling and cold drawing, which allow us to manufacture steel profiles with complex geometries and outstanding precision.
Types of Cold Working Processes
Several processes fall under cold working, each with specific characteristics and applications. Below we cover the most common ones, some of which are part of Montanstahl’s production methods, while others are widely used in the steel industry.
Cold Rolling
Cold rolling is used to produce thinner sections and profiles with excellent surface finishes and high dimensional accuracy. The process involves passing steel through rollers set closer than the material’s thickness, causing elongation, slight width increase, and minor thickness reduction. At Montanstahl, cold rolling is ideal for small profiles, enabling production in small batches starting from 500 kg. Products can be supplied in bars up to 6,000 mm or in coils, cut to length with ±10 mm tolerance.
Cold Drawing
Cold drawing pulls steel through a series of progressively smaller dies to reduce its cross-section and achieve the desired size with tight tolerances. Dies have progressively smaller diameters, requiring multiple passes until the exact dimensions and tolerances are reached. This method delivers very good surface finishes and allows for mechanical property adjustments. At Montanstahl, cold drawing is widely used for medium and large profiles, providing flexibility to customize characteristics for specific applications.
Stamping and Punching
Stamping and punching shape steel sheets or strips by applying high-pressure dies to cut, perforate, or form the material. While not part of Montanstahl’s core production processes, they are common in the industry for producing brackets, perforated panels, and custom components.
Bending
Bending changes the shape of steel sections without altering their thickness, creating angles, arcs, or curves. Though Montanstahl focuses primarily on rolling and drawing, bending is often part of downstream processing for custom profiles.
Benefits of Cold Working Steel
- Increased strength and hardness due to strain hardening
- Superior surface finish, smooth and uniform, ideal for polishing or brushing
- High dimensional accuracy with tight tolerances
- Ability to manufacture complex shapes and small cross-sections
- Improved wear and fatigue resistance
- Customizable mechanical properties for specific applications
Applications of Cold Worked Steel
Cold worked steel is used across a variety of industries where precision, durability, and performance are critical, including industrial applications:
- Medical devices and surgical tools
- Automotive and aerospace components
- Transportation and railway infrastructure
- Manufacturing equipment and machinery
- Nuclear, shipbuilding, and pulp & paper sectors
- Architectural and interior design profiles
- High-performance fasteners, screws, and small precision parts
- Specialized blades for electric razors and industrial cutting tools
An example from Montanstahl’s production is a profile requested by one of our customers, used as hair trimmer blades for electric razors. These require steel grades with high carbon content for hardening at high temperatures, such as martensitic stainless steels and bearing steels.
Martensitic steels, such as AISI 410, contain chromium (11.5–18%), small amounts of molybdenum (0.2%–1.5%), nickel (max 2.5%), and carbon (0.08%–1.20%). They can be hardened by heat treatment, offering high surface hardness and wear resistance. For carbon steel alternatives, Montanstahl uses 100Cr6 and 42CrMo4, both with high carbon content for superior hardness and dimensional stability. Blade profiles are produced with tolerances down to ±0.03 mm and specific tip ranges (0.57–0.63 mm) to allow final sharpening with minimal waste. We supply them both in bars up to 5 meters and in coils, the latter reducing cutting waste by up to 5%.
Limitations of Cold Working
- Work hardening can make further forming difficult without annealing
- Not suited for very thick sections due to high force requirements
- Residual stresses may require stress-relief treatment
- Reduced ductility compared to hot worked steel
- Increased tooling wear due to harder material
Despite these limitations, cold working remains one of the most effective methods for producing high-quality steel profiles with superior performance and aesthetics. At Montanstahl, we leverage our expertise in cold rolling and cold drawing to deliver customized solutions for demanding industries worldwide.