Automotive and aerospace parts suppliers have found that bringing tool regrinding in house can reduce cost and expedite tool availability. They are being more proactive in their cutting tool management.

That means CNC tool grinding machines are not just for cutting tool manufacturers any more. Tool regrinding is increasingly a possibility for manufacturers that consume a high volume of tools, especially with harder materials driving up costs of tools and shortening their lifespans.

The cost of resharpening a tool is roughly 30 percent of the cost of a new tool. Consider that many end mills can be reground at least three times. Using the same end mill that has been reconditioned three times vs. purchasing four end mills equals about a 60-percent savings in tool cost, which can be a compelling case to perform this function in-house as opposed to using a third-party vendor.

Bringing Tool Regrinding In-House Has Many Benefits

It is not just the cost of the tools that should be considered when evaluating whether to bring tool regrinding in-house. The COVID-19 pandemic has taught parts suppliers and manufacturers that they need to reduce risks of supply chain disruptions beyond their control. Control of the tool regrinding function helps manufacturers with prioritization and with reaction time in emergencies.

Other benefits of having tool regrinding capabilities in-house include:

• Minimizing the loss of production if the right tool isn’t available when required.
• Added flexibility with additional solutions and shorter turnaround times.
• Avoiding overly long tool regrinding times, especially for dealing with unusual geometries.
• Eliminating the need to carry excess backup tool inventory.
• Saving time.

The investment in a tool grinding machine also will require a manufacturer to build its staffing capabilities. But just as that shop used to send out tools to be resharpened to a third-party vendor, they may eventually be able to offer these services to others, pending capacity issues. But some shops have turned the expense of tool regrinding into a profit center.

High-Volume Manufacturers Often Can Justify Cost of a Tool Grinding Machine

The sweet spot for tool regrinding is high-volume manufacturers that consume a lot of tooling, such as automotive and aerospace suppliers. These manufacturers often can justify  the cost of buying a tool grinding machine because they can’t afford to stop the production line. If a couple of spare parts are put into use, they may not have backups in stock to avoid costly delays.

The automotive sector often buys entry-level machinery, which is an incentive to keep tools sharp to lessen wear on the machines. High-volume producers can dial in when to regrind tools, which keeps the machines running at a highly efficient rate. They have the ability to maximize both machine life and tool life. In fact, rebuilding workhouse machines is popular for regrinding customers.

Since resharpening doesn’t usually involve heavy cuts (such as for flutes or gashes), tool regrinding doesn’t require a lot of horsepower to do the work, which means regrinding machines can last a long time.

While Machines Are Easier to Use, Tools Become More Complex

As with parts and grinding wheels, tools are becoming more complex and are made from harder-to-machine materials. Cutting more composites for parts also means tool wear is higher. The cost of PCD tools is quite high, so the savings from resharpening in-house is going to be higher. This is another trend driving the growth of in-housing tool regrinding.

Not every tool can be reground or resharpened. For example, a drill or reamer needs to make the same size hole in every part, so you can’t change the diameter of the drill. The end is the only portion of the tool that can be touched. But an end mill that cuts a shape to a certain size can be reground. As the end mill gets smaller, the settings can be adjusted so it cuts more or less material.

It also might not be practical to regrind a smaller tool — say a 5- or 6-millimeter carbide end mill that might become weakened with the loss of minimal material. It probably makes sense to replace it with a new one. But for bigger pieces of carbide, there will be significant savings.

Tool Regrinding Adds Capabilities for Modifications, Specialty Tools

The ability to make minor modifications to a cutting tool gives customers another reason for having a tool grinding machine on the floor. Confronted with an unusual issue, it may otherwise take some time to order and receive a new tool.

Maybe a tool has a chamfer, which needs to be bigger. Or, if a corner radius needs to be bigger, a tool can be modified for that. A tool grinding machine may even be able to create a specialty cutting tool for milling machines.

Technology Innovations Will Lead to Longer Tool Life

New tool grinding machine technology features include automation and the ability to create a digital twin to monitor tool wear.

Some tool grinding machine builders offer automated regrinding systems for mixed batches based on RFID tags. As each tool is loaded for resharpening, the machine reads the RFID and adjusts the grind. The tool position inside the pallet can be swapped with another tool anytime if a tool needs to be resharpened in a hurry.

The digital scanning helps predict better tool life by monitoring wear, temperature, positioning and vibration. Software can also track what is in stock and where it’s located.

Find the Right Partner for Your Tool Regrinding Needs

Here at UNITED GRINDING North America, we understand the importance of tool reconditioning, from saving time and money to the peace of mind that comes with knowing you have more control over your production capabilities.

Contact us today to discuss how we can collaborate to solve your challenges and get the most out of your grinding technology.