The longer the service life of a cutting tool, the lower the cost of that tool, and the more effectively it can operate. So what is the best way to increase service life?
From a purely linguistic perspective, the term “service life” for cutting tools seems a bit counterintuitive. This is because it does not describe the time during which a tool sits idle and unused, but rather the exact opposite: Service life refers to the total time during which a cutting tool is in use (i.e., actually removing material) before it needs to be replaced. Time required to change the workpiece is therefore not included in the service life.
Replacing a tool, in turn, incurs costs in several ways:
- A new tool must be purchased and installed, while the old one must be reground or disposed of.
- It takes time to remove the old tool (and possibly regrind it later) and to install a new one.
- While the tool is being replaced, the machine is idle, and the manufacturing process comes to a standstill—the more frequently a replacement is required, the greater the production downtime.
- You face increased storage and procurement costs for your tool inventory.
Longer tool life thus ensures less machine downtime and enables more effective work overall, thereby reducing your production costs.
Purchasing new tools can be avoided by regrinding existing ones. Regrinding the tool edges significantly extends the service life of the cutting tool, thereby saving on the cost of purchasing new tools. The »edgeControl« measuring machine is helpful here. The device detects the greatest wear on a cutting edge. This allows the tool to be reground only as much as is actually necessary, down to the µm.
Learn more about wear marks and defects along the cutting edge
The fact that tool life is limited at all is due to simple physical reasons: Machining causes the tool to wear down; after all, the material it is made of is subjected to mechanical stress and also heats up.
This logically leads to the most important factors that influence service life:
the tool geometry, i.e., the specific shape of the tool,
the material from which the tool is made,
the specific machining conditions (particularly cutting speed, feed rate, and depth of cut),
the material from which the workpiece is made (the workpiece material or cutting material), and
the temperature or changes in the tool’s temperature.
From these factors, it can be deduced that, for example, lower machining speeds, a precisely calculated depth of cut, the use of suitable coolants, and, of course, the use of tools made of high-quality material suited to the workpiece material can also significantly extend tool life in some cases, as they slow down tool wear.
Significant improvements can be achieved by implementing certain measures. At the same time, it is crucial to monitor the effectiveness of these measures during their day-to-day application. Here, it makes sense to utilize appropriate technologies for tool monitoring and tool management.
Wear manifests itself in various ways on a cutting tool. Essentially, there are two types of wear in cutting tools: flank wear (as the name suggests, on the flank of the tool) and gouge wear, which occurs on the rake face.
The width of the wear marks and the depth of the pitting are often used as criteria to determine whether a tool needs to be replaced or reground—in other words, whether its service life has expired (“service life criteria”).
In addition to face wear and pitting, there are other forms of wear:
- scaling (i.e., the oxidation of the tool surface by atmospheric oxygen, which can occur particularly at higher temperatures),
- chipping of the tool, and
- cracks, which can occur primarily due to fluctuating mechanical and thermal stresses.
Especially for tool wear caused by high or rapidly fluctuating temperatures, it is helpful to use a suitable coolant adapted to the situation. This can significantly extend the service life of your precision tools.
As tool wear increases, the tool’s cutting performance naturally decreases; however, as with a nicked knife, the accuracy and quality of the workpiece suffer most of all.
Longer tool life, more operating hours
Extending the service life of your tools through appropriate measures and the selection of high-quality tools offers many advantages. You reduce machine downtime, optimize production schedules, 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 actually produce increases significantly in the medium and long term.
With ZOLLER TMS Tool Management Solutions, you always have a clear overview of your tools. Right from the moment goods are received, you can measure all parameters, sort out defective tools, and file a complaint if necessary. The ZOLLER »flash« software allows you to verify whether the tool life promised by manufacturers is actually being achieved. This saves money and ensures high-quality products.