A brief guide: Deburring

The machine has long since come to rest, and the component is basically finished. Basically. But its edges still bear features that don’t belong there: fine protrusions, barely visible but tangibly sharp. This is where Tobias Kosch and Tayeb Lahmek, deburring specialists at MTU Aero Engines, get to work. As they reach for sanding belts, milling cutters, and measuring tools, there’s one key thing they bring to bear: a wealth of experience.

“Like the name suggests, deburring involves removing protruding burrs and smoothly rounding off edges,” Lahmek explains. Burrs form during nearly every machining process, such as milling, drilling, or turning. As these processes remove metal, they can cause deformations and leave behind tiny protrusions. What seems harmless at first can become a problem later on: Burrs can initiate fatigue cracks, cause imbalances, or, in the worst case, lead to engine failure—for example, if a rotor disk ruptures. What’s more, the small protrusions pose a risk of injury to employees.

The final step is what matters

For Kosch, deburring is more than just finishing work. “We’re the final step in the manufacturing process,” he says. “Without us, it all falls apart.” It’s true that components don’t leave the production line until their every edge meets the specifications. Depending on the component, specific fillet radii are required, often in the range of tenths of a millimeter. Removing too much material is just as critical as removing too little.

This is because any change to an edge affects the component’s geometry. “Drawings and technical specifications define exactly how we need to machine each edge. Some areas require only a slight chamfer, while others require a specific radius. The key thing here is to preserve the component’s original function—or make it possible in the first place,” Lahmek says. In some cases, the fillet or chamfer is made visible and measured using special impressions. Only when the dimensions, surface, and transitions fit exactly is the component approved for assembly.

Achieving the perfect edge step by step

The deburring process varies depending on the component, but always follows a clear principle. First, sharp edges and burrs are carefully removed using a milling cutter to create an initial contour. This contour is then rounded off using a sanding belt. The final step is polishing, which smooths out the transitions and improves the surface finish.

MTU is currently testing how technology might complement the deburring process. This involves having a robot handle clearly defined, physically demanding tasks—especially when working on heavy or large components. “It’s a new technology and one we’re still developing,” Kosch says. “But it helps us maintain consistent quality and make our work more ergonomic.”

Handcraftsmanship is indispensable

However, both deburring specialists consider one factor to be crucial: Handcraftsmanship is here to stay. “There’s no replacing dexterity and a delicate touch,” says Lahmek, who’s been working in this profession for nearly three decades. “They’re not something you can develop from one day to the next; it takes experience. It’s a kind of art.”

In the end, you’re left with a perfect component that has no sharp edges and no visible signs of machining. For Kosch, that’s exactly what makes deburring so special: “You can’t see it, but you notice right away when it’s missing.”