Reconditioning: “Toolmaking know-how is required”

Performance News: Why are tools reconditioned at all?

Jürgen Freund: Customers that use particularly valuable tools are the ones that benefit hugely from this. They simply need to purchase fewer new tools if the ones they already have in the production process can be re-used several times. And the reconditioning of worn-out tools is possible in many application areas.

And what does it involve in concrete terms? Are the tools simply recoated?

No, it involves much more than that. Whether a tool really achieves optimum performance when used in a machine depends on the interplay between cutting material, blade geometry and coating. That makes very high demands on the reconditioning process. The tool edges have to be reground to high precision and after recoating the thickness of the coating has to be exactly the same as that of a new tool. What is more the surface has to have the prescribed roughness.

So in the end the customer gets a reconditioned tool that’s just as good as a new one?

That’s precisely what we can guarantee at LMT. On the one hand, of course, we know all there is to know about the engineering and design of our tools. This know-how flows directly into the demanding process of reconditioning – from decoating and sharpening to deburring and recoating. But there is something else that is also very important: if you want to be able to guarantee a tool has its original quality after reconditioning, you also have to apply the original coating. Otherwise, of course, performance decreases.

How much depends on the having the right coating?

A very great deal. When we developed the Nanosphere coating, for example, we were able to increase the tool life of hobs by a third – and that with significantly higher cutting speeds. This enormous performance hike must not be lost after the first recoating. At LMT we guarantee the reconditioning of Nanosphere hobs to the standard of new tools throughout the entire life cycle.

How does all that fit into your customer’s production process?

Of course, that’s a rather important point. The service cycle has to be perfectly integrated. We collect the tools and inspect them and then after reconditioning they are taken straight back to the customer. That ensures that every tool is available again in the shortest possible time. Furthermore, we guarantee this standard of service in all major markets. LMT operates a global network with coating centres in the USA, Germany, the Czech Republic and China. Additional locations – for example, in India – are currently being set up. Our centres can recondition hobs with the innovative Nanosphere coating within a few days.

Does component quality also benefit?

Yes, of course. Conventionally coated gear hobs that no longer achieve their initial performance after a first recoating or whose surface has been modified by using a different coating can produce unwanted component tolerances during their second or third use. That definitely doesn’t happen with Nanosphere hobs.