Step-Tec spindles – Swiss high performance for precision machining

Step-Tec spindles – Always one step ahead

Step-Tec is one of the leading manufacturers of high-speed and precision spindles for demanding CNC machining. Since 1995, the Swiss company has been developing and producing motor spindles for tool and mold making, production companies, and the aviation industry. With over 20,000 spindles in use worldwide, Step-Tec has established itself as a technology leader.

As part of the GF Machining Solutions Group, Step-Tec combines Swiss precision with state-of-the-art spindle technology. The HSK, HSC, and HPC spindles are designed for extreme speeds, thermal stability, and maximum repeatability—essential in tool and mold making as well as high-end machining.

Three innovations that set Step-Tec apart

1. Opticool and COOL-Core cooling systems Step-Tec was a pioneer in the development of innovative cooling concepts. The COOL-Core system with cooled spindle shaft reduces natural thermal shaft expansion by half. This results in maximum thermal stability and precision right down to the tool tip – a decisive advantage in fine machining and long machining cycles.
2. Compact design with maximum power density The extremely compact and stable design of Step-Tec spindles offers proven reliable performance for machine manufacturers and end users. High-quality bearing systems and optimally matched preload types ensure minimal axial displacement of the spindle shaft, resulting in improved accuracy, longer spindle life, and greater process reliability.
3. Integrated sensor technology and digitalization Step-Tec spindles are equipped with state-of-the-art sensor and data management technologies. The integrated vibration sensors and axial movement sensors enable predictive maintenance and maximize machine availability.

Step-Tec spindle platforms – The right solution for every application

Step-Tec offers standardized spindle platforms with common components and interchangeable designs:

• HVC 120 and HVC 140 – High-performance spindles for high-speed machining of aluminum
• HPC 190, 240, and 290 – Powerful spindles for machining steel, titanium, and superalloys
• Grinding and turning spindles – For precise surface and cylindrical machining
• Customized solutions – Tailored to individual manufacturing requirements

With speeds of up to 42,000 rpm (originally developed for Mikron AG in 1992) and performance levels perfectly tailored to the machining task at hand, Step-Tec covers the entire spectrum of modern machining.

Proven quality in demanding industries

Step-Tec spindles are key components in GF Machining Solutions' 3- and 5-axis machining centers and contribute significantly to the class-leading performance of these machines. The spindles are used in:

• Aerospace – Machining complex structural components made of titanium and aluminum
• Automotive industry – Precision parts with the highest requirements
• Energy technology – components for turbines and generators
• Medical technology – Micro-precision parts for medical devices
• Tool and mold making – Complex molds with micrometer precision

Step-Tec – Swiss engineering meets state-of-the-art technology

At the Biel (Switzerland) site, development, assembly, and repair work closely together. With its own technology center for production and high-tech products "Made in Switzerland," Step-Tec guarantees the highest quality standards. All strategic components are manufactured in-house—for controlled manufacturing processes and consistent quality.

Step-Tec continuously invests in research and development as well as in digitalization. The goal: to offer customers decisive added value through innovative digital solutions and to achieve perfect rotation.

KERN GmbH – Your expert for Step-Tec spindle repair

When a Step-Tec spindle fails, entire high-speed processes often come to a standstill. Our team analyzes, repairs, and tests Step-Tec spindles using state-of-the-art measurement technology, high-precision balancing, and OEM-compliant processes. Fast, reliable, and perfectly tailored to your HSC machining needs.

We are familiar with the design-specific features of all Step-Tec series —from HSC milling spindles to high-frequency models. Every repair is carried out using hybrid bearings, thermal fine adjustment, and documented concentricity measurement.

Our Step-Tec services:

• Complete diagnosis including vibration, concentricity, and thermal characterization
• Certified repair with replacement parts precisely tailored to each Step-Tec series
• On-site service – removal, installation, and recommissioning directly at your premises
• Express service with short response times for urgent repairs
• Exchange spindle service – Refurbished Step-Tec spindles available immediately

Spindle failure? We are ready. A failure of your Step-Tec high-speed spindle often means downtime, quality problems, and high costs. We analyze and repair Step-Tec spindles using state-of-the-art measurement, diagnostic, and balancing technology—precisely, quickly, and perfectly tailored to the performance of your HSK, HSC, or HPC spindle series.

Lower costs, less risk, less downtime—and in return , full dynamics, rotational speed performance, and thermal stability back in your production.