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    October 30, 2023

    What Is EDM Machining and How Does it Work?


    If you didn’t know, every part that gets physically made comes with a set of tolerances. When you measure the final part, you’ll notice that the numbers don’t reflect exactly what you have on your drawing. This discrepancy can come from machine chatter, imperfections in setting up the part, or inconsistencies with the raw material used. An effort to get the finished part closer to the dimensions on your drawing translates to aiming for tighter tolerances.

    In this quick guide, our expert machinists will suggest a few tips that will help you achieve tighter tolerances on every part that you machine.

    Control the Temperature

    A temperature-controlled machining environment gives you the best chance of hitting tighter tolerances. Metal that’s too hot or too cold will actually change in dimensions, resulting in cuts that aren’t exactly what your drawing called for.

    This is another reason why enclosed milling workstations are preferred over standard 3-axis machines.

    Stick to Experienced Machinists

    EDM-Machine-2-768x512It might not seem obvious, but an experienced machinist can work wonders when it comes to hitting tighter tolerances. Their experience will tell them the right cutting speed, the right tool to use, and exactly how to set up the material for each cut.

    Time after time, our experienced machinists create parts that hit much together tolerances than our rookie machinists. If you can’t afford to redo your parts that need to be incredibly precise, then stick with shops that have a lot of experience, like our crew at Rapid Axis. 

    Pick the Right Tool for the Job

    Would you use a saw and spoon to hang a picture frame? No way. Using the right tools for any project will help with the overall success that you see, and the same is true for CNC milling and other machining. Using the right machine, cutting tool, or bit will greatly reduce your overall tolerances.

    We have certain cutting heads that are specifically designed to reduce tool chatter, further limiting the deviation between our drilled holes and your drawing’s specs.

    This is another factor that comes with more experience in the machine shop.

    Make Sure Your Material Suppliers are High Quality

    Hitting tight tolerances doesn’t just fall on the shoulders of the machinists, it also relies heavily on the sourced material. Using “cheap” raw material typically comes with more flaws and inconsistencies across the metal. 

    However, more expensive and higher quality materials will directly result in parts that come closer to the dimensions you specified. 

    Use High-Quality Machines

    Beyond the source material and machinists, there’s another piece of the puzzle worth looking at: the actual CNC machines. A very old machine might have performance degradation or shortcomings in the technology. “Budget” machines often run into repeatability problems and issues hitting tight tolerances.

    With more expensive and higher quality CNC milling machines, the machinist has a much better chance of hitting your tight tolerances.

    However, it’s worth pointing out that an experienced machinist can do great work on a low-quality machine. Still, it’s always better to stick with machine shops that have higher-tech and better-quality machines.

    Splurge on Quality Control

    Quality control is the idea of improving the precision, accuracy, and repeatability of every part a machine shop makes. Shops with quality control departments often charge a little extra for their parts, but their parts also come with higher confidence that they’re made correctly.

    When you choose a machine shop that offers quality control efforts, you’ll get parts that have tighter tolerances. 

    Behind the scenes, the shop will throw out any attempts that don’t come close enough to your specifications. This can only be determined after precise measurements are done in the shop — an extra effort that low-cost machine shops will skip on.


    Now you have a better understanding of how you can hit tighter tolerances with all of your parts. When it comes to traditional machining, choosing the right shop will greatly reduce your overall part tolerances. For great results, you can trust our team at Rapid Axis. Our professional machinists have plenty of experience in the industry, resulting in better tolerances on all of your parts. Get a free quote today

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