Hand-held calipers are multi-faceted tools that have tons of uses when working on your car, particularly if you are doing custom fabrication work that is common for more advanced car projects such as custom engine and drive train swaps, custom cosmetics for show cars, etc. Using calipers, you can measure a myriad of part dimensions including lengths, widths, hole diameter, material thickness, and so on. For this reason, they are extremely useful for any type of machining or fabrication work. In addition to verifying dimensions of machined parts that come off your lathe or mill, they are also ideal for measuring automotive maintenance items such as brake rotor wear and verifying internal engine component dimensions meet specification.
The three most common types of calipers used by mechanics are Vernier, dial, and electronic calipers. Each of these three choices has distinct advantages and disadvantages. Due to this fact, we are often asked which type of caliper would work best? The answer to whether you choose Vernier versus dial versus electronic calipers depends entirely on your situation. We have detailed the strengths and weaknesses of each type below.
Vernier calipers look are the most simple in construction, featuring two sliding scales that you can align to give higher precision measurements than a standard steel ruler can provide. The first scale shows large graduations (typically inches), while the second set of graduations show smaller graduations (usually 1/128 inches). To measure, you place your calipers on your component and look for the graduation lines that align which gives you the necessary information to do some simple addition to figure out your dimension.
The biggest advantages to Vernier calipers are their cost and the fact that they really don’t require any calibration. Since they are so simple in construction, cost of entry is extremely low. Another advantage to their simplicity is that there really isn’t anything to calibrate as they are basically just steel rulers that are attached to a set of jaws that slide past each other. This means that you can basically just throw them into your tool cabinet until the next use.
When it comes to disadvantages, the Vernier style caliper is probably the least used of the three because versus a dial or electronic caliper it tends to be more complex and slower to read, particularly for amateur machinists. That said, they are extremely functional once you learn how to use them and they are very cost efficient compared to their dial end electronic counterparts.
Compared to Vernier calipers, dial calipers are much more commonly used and were arguably the most common to find in mechanics’ toolboxes up until the early 2000’s. They feature a dial indicator which makes them very easy and intuitive to read. No battery is required to operate as they are entirely mechanical in construction, which makes them pretty much trouble and maintenance free with the exception of the occasional calibration. They are fluid resistant (i.e. no electronics to worry about in wet environments) which makes them an ideal choice in the presence of coolant (either engine or machining coolant) or oil (either engine oil or cutting oil), and they just require simple cleaning prior to storage to keep them in good condition.
Some of the disadvantages with dial calipers their size limitations and their sensitivity to dirt. It starts to get tough to find dial calipers much larger than 12-inches long (versus Vernier calipers which can be significantly longer), although you can occasionally find larger dial calipers if you really do some searching. Another challenge is that the dial typically only indicates only one type of units, so prepare to do some unit conversions between metric and SAE units unless you have two sets of calipers. Dial calipers are also sensitive to dust and grime which can gum up the slide pretty quickly, so keeping them clean is an absolute must. Finally, if dial calipers become damaged, they are difficult and expensive to repair. Their internals are intricate, so common repairs are hard to do without the help of a professional which can often be cost prohibitive.
Digital or electronic calipers are arguably the most common used type of caliper found in auto repair shops and manufacturing environments. They come in many lengths and sizes to fit every budget and project, they are available with different jaw lengths and styles, and thankfully they can convert between both metric and inches with the push of a button. Digital calipers are definitely easier to read than Vernier and dial calipers, and some of the high-end models have data output and memory features among other functions. They can set the zero point at any place in the measurement range which makes them beneficial if measuring in reference to pre-existing dimensions.
While digital calipers are becoming more and more evolved as far as functions available, they still face the problem that pervades the technology industry: battery life. The lower priced caliper sets have batteries than don’t last very long and can require frequent changing, which is mildly annoying in the best of cases. The cheaper versions can also face environmental issues with liquids, and if they become damaged they are difficult enough to fix that you might as well just buy a new caliper. Fortunately, the best digital calipers don’t really have these issues though.
When it comes to choosing between dial versus digital versus Vernier calipers, it all boils down to your specific use case. For those who prioritize ease of use and are willing to pay to play, we recommend a nice set of electronic calipers as they offer a more extensive feature set versus dial or Vernier versions. We also recommend avoiding cheap electronic calipers as they can cause more problems than they are worth. For those who want the absolute cheapest set of calipers money can buy, Vernier calipers are the ticket and still remain accurate enough to get the job done. Finally, dial calipers fall right in the middle in terms of cost and ease of use, and are always a good choice for this reason.
Overall, the calipers that are best for you depend on your budget, what you need to measure, and what environment you plan to use the calipers in. There is most certainly a style and budget for everyone. We hope that you have found this article informative and that it helps make your decision a bit easier. Happy wrenching!