What are the Tightest Possible Machining Tolerances?

We are often asked what are the tightest possible machining tolerances we can hold for any given part. Of course, the answer is not always straightforward and can depend on a variety of factors, some of which include: Part geometry, material, manufacturing method and more. That said, there are some general guidelines that can help, which we’ll explore more in this post.

Did you know advancements in micromanufacturing technologies allow for tolerances as small as 1 micron (0.00004 in)!

Standard Machining Tolerances

Tolerances from ± 0.005″ down to ± 0.002″ (± 0.127 mm down to ± 0.050 mm)

Standard machining mills and lathes commonly hold tolerances ± 0.005″ down to ± 0.002″. These machines are capable of consistently maintaining tolerances within this range, and are suitable for the vast majority of machining applications. If these tolerances work for your application, we recommend keeping the design simple, and utilizing these tolerances wherever possible.

Smallest Micro Machining Tolerances

Tolerances from ± 0.002″ down to ± 0.0004″ (± 0.050 mm down to ± 0.010 mm)

Multi-axis micromachining centers and lathes with advanced controls and monitoring systems are capable of much tighter tolerances. These technologies ensure meticulous control over every aspect of the machining process, enabling exceptionally tight tolerances. Tight tolerance micro machining has found significant applications in the fields of medical devices and aerospace. The healthcare industry demands exceptionally precise and reliable components to ensure patient safety and effective treatment. Micro machining plays a crucial role in manufacturing medical devices that require intricate designs and tight tolerances.

Smallest Micro EDM Tolerances

Tolerances from ± 0.001″ down to ± 0.0004″ (± 0.025 mm down to ± 0.010 mm)

Micro EDM technologies provides a similar range of tight tolerances as that of micromachining. While micromachining uses cutting bits to form material, micro EDM erodes material using electrical discharges delivered by die or wire. Hence, micro EDM has an advantage over micromachining where part features (e.g. sharp inside corners) are well suited for wire or die, over end mill. Micro EDM also exhibits far less force on the workpiece as compared to micromachining. Thus micro EDM allows for tighter bend and concentricity tolerances on longer parts. However, micro EDM will not work for all applications. Due to it’s usage of electrical discharges, this technology only works on conductive materials and is mainly used on metal.

Smallest Femtosecond Laser Machining Tolerances

Tolerances from ± 0.0004″ down to ± 0.00004 (± 0.010 mm down to ± 0 .001 mm)

Femtosecond Laser machining provides unparalleled tight tolerances down to 1 micron! This technology uses ultra fast laser pulses to remove material and form a workpiece. The highly focused laser and short pulsation allows for extreme precision. Furthermore, femtosecond laser works on a variety of materials, both conductive and non-conductive. Additionally, the use of laser applies negligeable force to the workpiece to ensure tight concentricity and minimal bending on longer parts. This technology is best reserved for the fine features that need it the most, as bulk material removal can be slower than traditional methods.

In need of tight tolerance micromachining? Let us help.

We manufacture micro components and assemblies in accordance with Medical Device and ISO regulations.

  • Extensive Quality Management Systems
  • ISO 13485:2016 Certified
  • Class ISO-7 Clean Room

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