Forging

Forged rings start their life on a ring rolling mill, where accuracy is key, but it’s the final sizing that ensures the rings meet their exact dimensions. This step perfects the roundness of the ring and reduces or even eliminates the need for final machining, saving on material waste and production time.

Grotnes forging expanders are employed for precisely adjusting cylindrical parts, enhancing their microstructure and material properties. Starting as cylindrical preforms, seamless rings are pierced and shaped on a ring roller. After possible heat treatments and machining, the final sizing corrects any distortions and stabilizes the part’s structure, achieving high precision for both inner and outer diameters with minimal machining allowances.

Operational Efficiency with Advanced Tooling


Grotnes offers a versatile range of expanders, including both “Push” and “Pull” types, accommodating a wide array of diameters and part heights with stacked tooling options. With no fixed tonnage limit, our machines are customizable to meet specific customer needs, ensuring flexibility across various applications. Operators set up the machine for automatic operation, place the part using lifting equipment, and start the automated sequence to expand the part to the desired dimensions with segmented dies.

Comprehensive Control with Advanced HMI



The expander’s Human-Machine Interface (HMI) provides complete control over the forging process, allowing operators to input parameters. Features include gauging mode to measure ring diameter, manual mode for hands-on control and password protection to secure operations and sensitive data.