Tool – Vernier Caliper

The Vernier Caliper is a tool for measuring small dimensions (length, width, thinkness and diameters). OBS: Do not confuse it with thickness gauges, use to make very precise measures of even small thicknesses (10mm or less). 

Its big advantage in relation to a ruler, or a mesuring tape, is the measuring accuracy, provided by its jaws (upper and lower) and the gauges (in case of gauge / digital models).

Its utilities, considering DIY involves all the areas where you need to create or adapt objects:

  • 3D Printer: Essential – It’s important to know the exact sizes of the objects (printed or not) to make sure they fit on each other.
  • Metalwork: Essential
  • Woodwork: Suggested

 

Specifications

Main Scale
The verniers main scale have markings in centimeters (at the bottom of the scale) and inches (at the top of the scale). The centimeters are divided in 10mm, and the inches in 1/10in.
It’s important to remember that some models have markings only for the unit used in the country they are made.

External Measuring
Using the lower jaw (the biggest one), it’s possible to measure the external dimensions of an object.
  

Internal Measuring
Using the upper jaw (the smallest one), it’s possible to measure the internal dimensions of an object (diameter of a hole, for example).
  

Depth Measuring
Sometimes it’s just not possible, using the jaws, to measure the dimensions of an object, like the inner depth of a box, or even it’s floor thickness. For this situations, it’s possible to use the depth measuring blade, to be extended out off the end of the scale until it touches the “floor”.

Thumb Screw
This small wheel like piece, when operated with the thumb helps to move the scale with better acuracy.
 

Locking Screw
The locking screw can be usefull, at least, in two situations:

  • When one cannot see the scale or the gauge/digital, it’s possible to lock the jaws and the scale. Then, just get the vernier off the object and look at the measuring result.
  • Marking a guideline to allow a more precise cut. Works well on cardboard, wood and plastics. It’s not recommended to use this trick on metal, because it can wear out the jaws tips.

  

Models

Sizes
There are several different sizes of vernier calipers, but the most common one is 6in (15cm).

Material
In general, they are made of plastic or metal (better quality, more expensive).

Universal
The universal verniers are simplest, but alse the less accurate, counting only on the scale for measuring.

Gauge
They are more accurate calipers, very popular on the last century, before the digital ones.

Digitals
As accurate as the gauge ones, but with digital display are easier to read. The need for batteries can be considered a disadvantage.

Other Models
There are many other model, having different/more specific jaw types (for measuring body fat, for example), but they are not the models used on DIY projects.

 

Tips

  • Prefere metal calipers. The plastic ones are fragile and tend to take damage easily.
  • It’s worth spend more money on a gauge / digital caliper, because they make easier to read the fractions of in/mm.

 

Where to Buy