Be advised that it is nearly impossible to take readings near the end of the ranges of these calipers. However, 8-inch, 12-inch, and even longer calipers are available. These are the most useful because they can be easily handled. The most common dial calipers have a measuring range from zero to six inches. At this point, measure with the unworn surfaces or have the calipers repaired. Then hold them up to the light and if they're worn you'll see light shining through the gaps. To check for wear in the jaws do this: clean them and close them. 0001').Ĭalipers should be frequently checked for accuracy using a gage block, or gage block combinations. They're perfect for all sorts of quick measurement and can be used as a preliminary source before moving on to more sensitive tools such as micrometers (.0001'), depth gages or dial indicators (.0005' and. 001' graduations and are accurate to ± one graduation (per 6') if none of the measuring surfaces have been worn, bent or damaged. If you need to span a larger diameter hole you can always get a depth bar attachment which will make your caliper function somewhat like a dial depth gage (see below).Ĭalipers have. The depth measurement is fine for small diameter holes and can extend all the way to 6 inches. One or two models have attempted to combine both systems on one dial but that's confusing and bound to lead to errors.ĭial calipers offer four measuring capabilities: outside dimensions-such as diameters-measured with the large jaws, inside dimensions measured with the smaller jaws, depth measurements obtained with the extending rod, and step measurements taken with the front of the tool.Īn optional Centerline Accessory Kit will also allow you to easily measure distances (center to center) between holes, groove diameters and undercuts where the jaws alone would be unable to reach. That's no problem if you never need to switch systems. Count on it.įor another, having a dial limits the calipers to being either metric or inch reading. For one, all those gears and parts will eventually malfunction. While dials may be an advantage, it causes all sorts of problems. The dial is pretty large and you probably won't have to squint to take a reading. The vernier scale can be small and you may have to resort to glasses or even a magnifier to read your vernier. This makes it easier to read for some people. Dial Calipers - Digital Calipers - Vernier Calipersĭial calipers are like vernier calipers with a dial.

How to read calipers