Manufacturers of dental burs, rotary tools for the medical sector, or high-end small cylindrical components are well aware of the problem: marking is the final step in the production cycle, but it is also the first thing the end customer sees. UDI codes, logos, colored ISO identification rings, diameters, and lot numbers must be legible, permanent, and consistent around the entire circumference of the part—on components that often do not exceed 20 mm in diameter and have dimensional tolerances achieved through grinding.
With these volumes and geometries, the limitations of traditional marking systems quickly become apparent. Loading parts one by one onto a single spindle takes up operator time and breaks up the cycle. Rotation on such small components amplifies any mechanical play: a misalignment of just a few centimeters between the rotation axis and the laser focus results in a mark that “drifts” along the circumference. And finally, there is the issue of durability: in the medical field, the marking must withstand citric and nitric passivation, repeated sterilization cycles, and salt spray testing—conditions in which a traditional fiber marking tends to degrade or discolor.
TowerSteel was developed to address all three of these critical issues simultaneously: placement productivity, mechanical precision, and long-term marking quality.
A structure designed for precision, not adapted
The machine’s base is a structure made entirely of welded, stress-relieved, and milled steel. This is not a minor design detail: the post-welding stress relief eliminates residual stresses in the frame, and the subsequent milling ensures the flatness and perpendicularity of the reference planes on which the axes and spindles are mounted. The result is a machine that is rigid, thermally stable, and repeatable—a necessary condition when working with small-diameter parts, where the permissible error in the focal position is measured in hundredths of a millimeter.
This design philosophy is the same one that LASIT has been applying for years to machines intended for precision machining: recirculating ball screws, motors with integrated encoders, and components sized to maintain performance over time—not just during testing.
The multi-spindle machine: up to 15 parts in a single setup
The feature that truly transforms day-to-day operations is the multi-spindle system: the operator loads up to 15 cutters in a single setup, and the machine marks them all in automatic sequence, each at 360 degrees.
The operating principle is simple but requires high-performance mechanics. A 600-mm X-axis moves the scanning head along the entire array of spindles, positioning it over the workpiece to be marked each time. The beam always operates perpendicular to the surface of the rotating component: this ensures that the energy is distributed uniformly along the entire circumference, without the distortions and variations in power density that would occur when marking over a wide area with variable angles of incidence. Whether on a 2-mm-diameter milling cutter or a 20-mm component, the marking quality remains consistent from the first spindle to the last.
The impact on the workflow is tangible. The operator is no longer tied to the machine for loading and unloading each individual part: they load a full batch, start the cycle, and in the meantime prepare the next one or attend to other tasks. Setup time is spread across 15 parts rather than concentrated on just one, and the cycle becomes predictable and plannable—an aspect that those managing tool production in batches value more than any peak speed figure.
The Picosecond: Black Marking, Stable, Compliant
The light source chosen for TowerSteel is a picosecond pulsed laser. In the medical field, this is not an aesthetic choice, but a process-driven one.
The ultrashort pulse transfers energy to the material in such a short time that it minimizes heat input to the surrounding area. The result is a black, matte, non-iridescent mark: the contrast remains identical from any viewing angle and under any lighting conditions, a fundamental requirement for the readability of UDI and DataMatrix codes on polished cylindrical surfaces.
Above all, the absence of surface oxidation makes the marking resistant to typical industry treatments: salt spray, citric acid passivation, and nitric acid passivation. This is a decisive factor, because traditional fiber laser marking generally passes the first test but does not withstand the nitric passivation cycle—with the result that the code degrades precisely after the treatment that is supposed to make the component suitable for medical use. With picosecond marking, the marking enters the passivation process and emerges unchanged, retaining its properties even after repeated sterilization cycles.
Added to this is an operational advantage: picosecond sources have an estimated lifespan of around 100,000 hours of operation with virtually no maintenance, a significant factor for those who mark thousands of instruments per day.
Who It’s For (and Who It’s Not For)
TowerSteel is a specialized machine. It performs best on cylindrical components up to approximately 20 mm in diameter: dental and surgical burs, rotary tools, drill bits, reamers, and precision small parts that require 360-degree circumferential marking with high quality and compliance standards. It is the natural solution for those who currently mark parts one by one on a single spindle and have production volumes so high that the per-unit processing time has become a bottleneck.
However, it is not the right machine for those who primarily mark on flat surfaces, for components with larger diameters, or for those who require maximum versatility across highly diverse product families: in those cases, systems such as TowerMark or rotary-table machines remain the most sensible choices.
In summary: if you manufacture high-quality milling cutters or small cylindrical parts, if the marking needs to be black, permanent, and resistant to passivation, and if the single-load capacity is limiting your productivity, TowerSteel addresses exactly these three issues—with a mechanical design built to last.
Applications Manager | LASIT
Applications Manager at LASIT for over 20 years, Mario Palmieri oversees the management and development of the company’s laser laboratory. He is responsible for conducting sample tests for customers, supporting the automotive, medical, aerospace and electronics sectors in identifying the most suitable laser marking solution for their needs.
