No More Spot Checks: How HQ 5 Is Redefining Roller Hardness Testing
Hardness is the deciding factor, for every meter of roller
When you inspect a roll, you’re inspecting the heart of the rolling mill. Its hardness determines how long it will remain in service, how stable the process is, and the quality of the final product coming off the line. Yet even today, roll hardness is still mostly measured the same way it was decades ago: at specific points, manually, and by leaving marks on the surface. Together with Herkules, we at QASS have changed that. The result is the HQ 5, a roll hardness measurement system that captures the entire surface without touching it.
Why Traditional Hardness Testing Is Reaching Its Limits
Whether Rockwell, Vickers, Brinell, or UCI: All common methods use an indenter. As a result, they present four disadvantages in everyday rolling operations.
- Spot checks instead of the big picture: Measurements are taken at individual points. What lies in between remains unknown, including local weak spots.
- Marks on the surface: Every measurement leaves a mark on a surface that is supposed to be flawless.
- Time and Staff: Manual measurements demand skilled personnel and are prone to operator errors.
- Unnecessary material removal: Without an accurate picture of the hardness distribution, more material is often ground away than necessary to restore uniform hardness across the roll. This wastes material and shortens the roll's service life.
HQ 5: Two Specialists, One System
HQ 5 is a joint development by QASS and Herkules. We bring over 20 years of experience in process optimization, sensor technology, component monitoring, and quality assurance, as well as the expertise in non-destructive hardness testing provided by our µmagnetic technology. As a specialist in roll machining, Herkules contributes its in-depth understanding of roll grinding machines and roll shops.
The result is a system that measures the hardness of the roller noncontact, fully automatically, and in real time, directly during the machining process. Error-prone individual measurements are replaced by a comprehensive, precise hardness profile.
How HQ 5 Works: Hardness You Can “Hear” Magnetically
The principle sounds astonishingly simple. The structure of a roller's surface consists of millions of tiny grains that behave like tiny magnets. At rest, these micromagnets are randomly aligned and cancel each other out.
1. Excitation: HQ 5 generates an alternating magnetic field that forces the micromagnets to align in a common direction.
2. Resistance: The harder the material, the more it resists this reorientation. It is precisely this behavior, described physically by the Barkhausen effect, that reveals a great deal about the material’s mechanical properties.
3. Measurement: A ferrite antenna positioned just above the surface detects even the slightest magnetic changes with high precision.
4. Analysis: The data is processed in real time and displayed as a 3D hardness map of the entire roller.
The Result: The result: an accurate picture of the microstructure and hardness, without contact, without leaving an impression, and without interruption.
What HQ 5 Changes at the Roll Shop
100% surface coverage instead of spot checks. The HQ 5 scans the entire roller surface. Local hardness variations are reliably detected and visualized in 3D, non-destructively and during the process. No indentations, no rework. The roller remains fully operational immediately.
No labor costs for manual measurements. The measurement process is fully automated. Deviations are detected early. This increases process and operational reliability.
Longer roller service life. When you know the hardness distribution precisely, you grind only as much as necessary. Automated regrinding restores the original hardness with minimal material removal.
Seamlessly integrated into the machine control system. HQ 5 is fully integrated into the PGC-10 control system of the Herkules roll grinding machines. Operation, measurement, documentation, analysis, and real-time data processing all take place within a single system..
Conclusion: Measuring quality without damaging it
With HQ 5, roller hardness testing evolves from a random sampling ritual into a continuous, data-driven process. Roll shops gain visibility into every millimeter of their rollers, save on materials and labor, and extend the service life of their rollers.
For us at QASS, HQ 5 represents another step forward on our journey: not just testing for quality, but integrating it into the process, non-destructively and in real time.
Would you like to see the HQ 5 in action? Contact us, we'll be happy to show you what the system can do for your roll shop.