Micron-level machining at Tumag in Turnhout
At Tumag we combine High Speed Machining (HSM) with expertise in CNC machining, mould making and precision mechanics. From our facility in Turnhout we produce accurate components for customers across Europe who set high standards for precision, surface quality and reliability.
Using modern five-axis HSM machines, we produce complex components with tolerances down to micron level. Our technology is used, among other things, for the production of:
- mould components
- cutting dies and precision tools
- precision mechanical components
- electrodes for spark erosion (EDM)
- complex 3D geometries in hardened steel
Thanks to high spindle speeds, optimised toolpaths and a precisely controlled production process, we deliver components that meet the most demanding requirements in sectors such as healthcare, aerospace and the high-end electronics and automotive industries.
What is HSM milling (High Speed Machining)?
HSM milling, or High Speed Machining, is a milling technique in which thin chips are removed at very high spindle speeds and feed rates. Thanks to the lower cutting forces and limited heat input, hardened materials and complex 3D geometries can be machined to micron precision with a high-quality surface finish.
At Tumag, this technology is an essential part of our precision mechanical production.
Thanks to many years of experience and a well-equipped machine shop, we produce complex components that meet extremely high requirements for accuracy and surface quality as well as process stability.
High Speed Machining (HSM) vs conventional milling
In conventional milling, the focus is on relatively low spindle speeds and larger chip thicknesses. HSM milling works exactly the other way around:
- Much higher spindle speeds
- Higher feed rates
- Significantly lower average chip thickness
The lower cutting forces put less load on the tool and carry the heat away through the chip rather than letting it enter the workpiece. As a result, both the tool and the material stay in optimal condition during machining, which directly benefits accuracy and tool life.
The advantages of HSM milling for precision components
Superior surface quality
The high spindle speed and small chip thickness make it possible to achieve extremely fine surface roughness values, ideal for mould components, precision mechanical parts and complex geometries.
Higher dimensional accuracy
Because the process is much more stable and the heat is carried away with the chips, the workpiece is not subjected to thermal stress. This ensures consistent dimensional accuracy and minimal distortion.
Ideal for thin-walled and complex components
Thanks to the low cutting forces, HSM generates considerably fewer vibrations. This makes it possible to mill thin walls, sharp details, delicate structures and complex 3D surfaces efficiently and accurately.
Higher productivity through HSM milling
Although smaller chip thicknesses are used, the high feed rates and spindle speeds give HSM a clear advantage in throughput time.
HSM milling at Tumag: precision machining for moulds and precision mechanics
At Tumag we apply High Speed Machining to the production of complex, accurate components that require a top-quality finish. Our experience ranges from mould components to precision mechanical parts and special electrodes for spark erosion (EDM).
Machining hardened steel up to 60 HRC
We machine hardened steel up to 60 HRC without difficulty, which is essential for mould making and high-end tooling where wear resistance is a key factor.
Production of electrodes for EDM
In our HSM department we also produce sinker EDM electrodes in:
- Graphite
- Copper
- Tungsten copper (Elconite)
These electrodes are later used in our EDM machines for sinker EDM, ensuring a smooth and perfectly coordinated internal production flow.
Hardened steel grades where HSM milling makes the difference
For many hardened tool steels, conventional CNC milling quickly becomes inefficient as hardness increases. The combination of high wear resistance, hard carbides and thermal load causes rapid tool wear and unwanted heat build-up in the workpiece. In these situations, High Speed Machining (HSM) offers decisive advantages.
Thanks to higher cutting speeds, lower radial cutting forces and optimised milling paths, the heat is largely carried away through the chip instead of penetrating into the material.
Typical steel grades where HSM milling performs exceptionally well include:
- 2379 (D2 / X153CrMoV12) – Wear-resistant cold work tool steel for dies and cutting tools.
- K390 (PM steel) – Powder metallurgical steel with extremely high wear resistance and toughness.
- 2080 (D3 / X210Cr12) – Very hard cold work tool steel with a high carbide content.
- 2363 (A2) – Cold work tool steel, often hardened to around 60 HRC.
- 2344 (H13) – Widely used hot work tool steel for moulds and high-end tooling.
- 2367 – Tough hot work tool steel with excellent thermal stability.
- Vanadis 4 Extra – PM steel with a perfect balance between wear resistance and toughness.
- Vanadis 10 – Highly wear-resistant powder metallurgical tool steel for the most demanding applications.
These materials are typically hardened to levels ranging from 50 to over 65 HRC. It is precisely in this extreme range that HSM, or hard milling, excels at producing complex shapes, accurate contours and a mirror-smooth surface finish. Thanks to its stable process, HSM is the ideal choice for demanding applications in mould making, die making and precision mechanics.
Steel grades and typical hardness levels
| Steel | Typical HRC |
| 1.2344 | 48–54 |
| 1.2367 | 50–54 |
| 1.2363 | 58–60 |
| 1.2379 | 58–62 |
| Vanadis 4 | 58–62 |
| Vanadis 10 | 60–64 |
| K390 | 62–65 |
Tumag as your partner for complex HSM milling projects
When your project demands high accuracy and surface quality, HSM milling is the right technique and Tumag the ideal partner. We manage the entire process, from raw material to high-quality end product.
Are you looking for a reliable partner for the production of complex components? Then Tumag is the partner you need.
Frequently asked questions about HSM milling (FAQ)
When is High Speed Machining used?
HSM is mainly used in the production of moulds, dies, precision mechanical components and complex 3D shapes in hardened materials. The process is particularly suited to applications where high precision and surface quality are required.
Which materials can be milled with HSM?
HSM milling can machine a range of materials, including hardened steel, aluminium, copper, graphite and various engineering alloys. At Tumag we machine steel up to 60 HRC without difficulty.
Where is HSM milling applied?
HSM milling is used for, among others:
- mould making.
- Dies
- precision mechanical components
- electrodes for EDM
- complex precision components
Are conventional milling and HSM milling applied to the same workpiece?
Yes, in many production processes conventional milling and HSM milling are combined on the same workpiece. The two techniques each play a different role within the machining process.
In the first stage, conventional CNC milling is often used for roughing. This removes the bulk of the material and gives the component its basic shape.
Intermediate steps may then follow, such as: heat treatment or hardening, precision grinding of reference surfaces or mating surfaces
In the final stage, the component is finished by HSM milling. This technique is particularly suited to the precise milling of complex shapes in hardened steel, with very high dimensional accuracy and a fine surface finish.
This combination of techniques creates an efficient production process in which both productivity and precision are exploited to the full.