Are Digital Calipers More Accurate Than Dial?

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Whether you’re a full-time gunsmith or it’s just a pastime, there will come the point where you’ll wonder whether you’re using the best calipers for your needs.

So, are digital calipers more accurate than dial? The answer is more involved than you’d expect.

Are Digital Calipers More Accurate Than Dial?

Digital calipers are more accurate than dial calipers since dial calipers are always off by 0.001 inch for roughly 25% of the needle revolution. You can check this on your caliper by checking a pin set every 0.010 for 0.100 of range.

Person using a dial caliper

Furthermore, unlike dial calipers, digital calipers do not use gears for measurement. Instead, they have copper pads and comb-like structures that form a grid of capacitors. When the comb slides over the copper pattern, the capacity between the plates changes, and the small changes in capacitance help calculate a highly accurate measurement.

Why Do Some Gunsmiths Think Digital Calipers Are Unreliable?

Digital calipers are preferred by many since they can switch between metric and imperial systems at the press of a button. Further, reading a digital caliper’s output takes no effort. The results are instantaneous, and since these tools don’t use a rack-and-pinion system, accidental knocks don’t render them useless.

However, these operate on batteries, which can run out at any moment, which is the biggest advantage of owning dial calipers because they don’t rely on batteries. Furthermore, if there’s a lot of moisture in the working area, the electrical components can malfunction and give out a wrong reading or stop working altogether.

Another reason why some gunsmiths think digital calipers are unreliable is that, on rare occasions, the presented value can be inaccurate due to the pressure applied or the quality of the tool.

But this doesn’t take away the fact that digital calipers are more accurate than dial calipers in general because of the display of measurement. With digital calipers, it’s easy to measure to three or even four decimal places quickly.

Digital caliper

Is There a Way to Make Dial Calipers More Accurate Than Digital Calipers?

While digital calipers are more accurate in general, gunsmiths shouldn’t shy away from using the tools available to them that they are comfortable with. Some gunsmiths will always pick dial calipers over digital ones since they’re reasonably accurate for the price.

  • Cheaper digital calipers tend to have a poor prognosis and break easily.
  • The body of thought here is that a dial caliper should suffice unless you require highly accurate measurements.
  • If you require an accuracy of one ten-thousandths of an inch, you could use a “tenths” micrometer.
  • Having a set of gauge blocks handy will ensure that any potential inaccuracies are rectified – whether you use digital or dial calipers.

Conclusion

Digital calipers are more accurate than dial calipers in two different ways, as they show results in three-four decimal places and the components used allows them to measure more accurately.

That said, you can trust a dial caliper’s measurements as long as it doesn’t have any dust and debris and has never been dropped or knocked around.

James Forrester is a lifelong gun and firearms owner, and an even bigger advocate for gun safety. He created KeepGunsSafe.com with the purpose of sharing helpful tips and educating others on how to keep guns and weapons safe and secure.