When does purchasing your own knife grinder become a profitable investment?
Should you outsource your industrial knife sharpening or invest in your own machine? While outsourcing may seem simpler, it can generate hidden costs. Find out at what point investing in your own grinder becomes a necessity for your company.
How does your own grinder reduce costs?
Financial analysis allows us to understand the full cost structure of tool maintenance. When outsourcing sharpening, it's important to consider not only the price of the service itself, but also several other economic factors:
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regular charges for regeneration services and logistics;
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funds frozen in additional sets of knives, necessary to ensure continuity of production during service;
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expenditure on administrative services, because the coordination of external orders involves the time of employees.
Example:
Let's assume the cost of sharpening one knife at an external company is EUR 22.
At a cycle of 40 knives per month, this translates to EUR 10,667 per year, excluding transportation and hidden costs. Additionally, the handling of preparing the knives for shipment, including packaging and proper protection for transport, must be taken into account.
A dedicated machine reduces unit costs to the cost of abrasive materials and operator time. However, if your company employs staff responsible for knife maintenance and replacement, they can easily be integrated into an automatic sharpening system – made possible by the GRAFS GR knife grinder. Operating the machine is simple, and after setting the grinding process, the machine automatically sharpens the knives, proceeds to sparking, and then automatically completes the process after a pre-programmed operating time.
Therefore, the operator is responsible for:
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Preparing knives for sharpening, cleaning them before placing them on the magnetic table,
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Mounting the knives on the magnetic table of the grinder, positioning the grinding wheel relative to the knives and starting the process,
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After sharpening, removing the knives from the machine,
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Cleaning the knives of any burr, coolant and performing proper maintenance.
To sum up: assuming that the company needs 40 knives per month, the monthly cost of operating the machine (coolant, grinding wheels and appropriate maintenance) is on average EUR 110 – which is, incidentally, approximately how much the company may spend per month on the logistics of sending knives externally for sharpening!
Depending on the level of advancement of the machine and the scale of operations, investing in your own industrial grinder allows for a return on investment (ROI) often after just 24–36 months.
Full control over blade parameters
Another aspect is the level of control over the technical parameters of sharpening. Professional tool sharpening services for companies, which we also provide at GRAFS, involve precise geometry reproduction and preservation of steel properties. However, investing in your own machine provides the unique opportunity for full, direct supervision of the process. This allows for:
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Complete control over blade geometry. You can precisely adjust the rake and clearance angles yourself, perfectly matching them to the specific material being cut — something more difficult to achieve with a standard service model.
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Guaranteed protection of steel material properties. Direct supervision of the grinding process and cooling system eliminates the risk of steel overheating and loss of hardness (HRC), maximizing tool life.
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Ability to continuously optimize the process. Having the machine on-site allows you to experiment and test different sharpening parameters to find the ideal settings for new materials and maximize production efficiency in real time.
Better time management and minimized downtime
Another argument for purchasing an industrial knife sharpening machine is better tool time management. Using external services requires adapting to the service provider's schedule and deadlines.
Owning your own machine brings complete control over the availability of sharp tools in-house. This translates into, among other things, the ability to respond immediately to breakdowns. In the event of sudden knife damage, it can be repaired on-site within minutes, instead of waiting days for its return from service. This reduces unplanned downtime from days to hours.
Equally important is flexibility and “on-demand” sharpening. With your own machine, there's no need to plan logistics in advance. Tools are sharpened precisely when the production schedule or their technical condition dictates, allowing for seamless management of your machinery.
Having the machine on-site also makes it easier to implement regular, preventative sharpening cycles. This allows you to keep all your knives at optimal performance, rather than reacting only when cut quality deteriorates.
Efficiency — the key question
A question that often comes up in companies deciding between external and in-house sharpening is:
WHAT IS THE EFFICIENCY?
It’s easy to calculate.
If a company has knives approximately 100 cm long, made of hardened steel with a hardness of 45–55 HRC, and each knife requires removing at least 1 mm of material, then this represents the average sharpening time on GRAFS machines.
For whom is owning a grinder the best investment?
While every company is different, several indicators clearly suggest that purchasing your own machine makes strategic sense:
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High frequency and scale of sharpening. The more knives and the more frequently they require refinishing, the faster the investment pays off and generates real savings.
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Rigorous quality requirements. When cutting precision directly impacts product quality (e.g., in printing or foil production), full control over sharpening parameters is invaluable.
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High cost of production downtime. In continuous operations (e.g., recycling), every hour of line downtime generates significant losses — so independence from external service is priceless.
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Use of expensive or custom knives. Controlling the sharpening process allows you to maximize the life of specialized and costly tools.
These conditions are most commonly met by companies in the recycling, wood processing, printing, and packaging industries. For them, investing in their own sharpening technology becomes a natural, strategic step in development.
Your own grinder: a strategic step in production optimization
The decision to purchase your own grinder is a move toward full control over a key element of the production process. It becomes an investment in operational independence, consistent quality, and long-term cost reduction.
If your company regularly uses tool sharpening services, exploring our range of professional equipment can be a step toward resource optimization.
We recommend industrial knife sharpening machines and accessories manufactured by GRAFS.
Our specialists will be happy to help you calculate your return on investment and select a model that perfectly suits your company’s needs.