The longer the tool life of a cutting tool, the lower the cost of that tool and the more effectively it can work. So what is the best way to increase tool life?
From a purely linguistic point of view, the term "tool life" for cutting tools seems a little counterintuitive. This is because it does not describe the time during which a tool stands around uselessly, but rather the exact opposite: tool life describes the total time during which a cutting tool is in use (i.e., actually performing material removal) before it needs to be exchanged. The time required to exchange the workpiece is therefore not included in the tool life.
Exchanging a tool, in turn, incurs costs in several ways:
- A new tool must be purchased and used, and the old one must be reground or disposed of.
- It takes working time to remove the old tool (and regrind it later, if necessary) and insert a new one.
- While the tool is being exchanged, the machine is idle and the production process is at a standstill – the more frequently an exchange is required, the more production losses there are.
- You have increased storage and procurement costs for your tool inventory.
Longer tool life therefore means less machine downtime and thus enables more effective work overall, reducing your production costs.
New tool purchases can be avoided by regrinding the tools. Regrinding the tool cutting edges significantly extends the lifetime of the cutting tool and thus saves on the cost of purchasing new tools. The »edgeControl« measuring machine is helpful here. The device detects the greatest amount of wear and tear on a cutting edge. This allows the tool to be reground only as much as is actually necessary, with an accuracy of µm.
Learn more about wear marks and defects along the cutting edge
There are simple physical reasons why the tool life is limited: machining causes wear and tear on the tool, as the material it is made of is subjected to mechanical stress and also heated.
This logically leads to the most important factors that influence tool life:
the tool geometry, i.e., the specific shape of the tool,
the material from which the tool is made,
the specific machining conditions (in particular cutting speed, feed, and cutting depth),
the material from which the workpiece is made (the workpiece or cutting material), and
the temperature or changes in the temperature of the tool.
These factors suggest that, for example, low cutting speeds, a precisely calculated cutting depth, the usage of suitable coolants, and, of course, the usage of tools made of high-quality material that is adapted to the workpiece can also significantly extend the tool life in some cases because they slow down tool wear.
Significant improvements can be achieved by implementing certain measures. At the same time, it is crucial to check the success of these measures during their everyday application. Here, it makes sense to use technologies that correspond to tools for tool monitoring and tool management.
Wear and tear manifests itself in different ways on the tool. Essentially, there are two forms of wear and tear on cutting tools: flank wear (as the name suggests, on the clearance/flank face of the tool) and rake wear, which occurs on the rake face.
The width of the wear mark and the depth of the pitting are often used as criteria to determine whether a tool needs to be exchanged or reground, i.e., whether its tool life has expired ("tool life criteria").
In addition to free surface wear and pitting wear, there are other forms of wear and tear:
- Scaling (i.e., oxidation of the tool surface by atmospheric oxygen, which can occur particularly at higher temperatures),
- tears from the tool, and
- cracks, which can occur mainly due to changing mechanical and thermal loads.
Especially for tool wear caused by high or rapidly changing temperatures, it is helpful to use a suitable coolant that is adjusted to the situation. This can significantly extend the lifetime of your precision tools.
As tool wear increases, the cutting performance of the tool logically decreases, but above all, as with a knife that has become blunt, the accuracy and quality of the part being machined suffer.
Longer tool life, more operating hours
Extending the tool life by taking appropriate measures and conducting a selection of high-quality tools has many advantages. You reduce machine downtime, optimize production schedules in the manufacturing area, work more effectively, and use your Precision tools for as long as possible without compromising the quality of your work.
Overall, this increases your productivity, as the number of operating hours during which you can produce increases significantly in the medium and long term.
With ZOLLER TMS Tool Management Solutions, you always have an overview of your tools. You can measure all parameters as soon as the goods are received at the goods receipt, reject defective tools, and make a complaint if necessary. The ZOLLER software »flash« allows you to check whether the tool life promised by the manufacturers is being adhered to. This saves money and ensures high-quality products.
