Protractors

Protractors are an essential piece of measuring equipment used to ensure precision and accuracy in the measurement of angles. Here at Cromwell, we have a range of protractors from market leading brands such as Moore & Wright, Mitutoyo and our own brand Oxford.

What are protractors?

A protractor, also referred to as an angle finder, is a precision measuring instrument used for measuring angles, in degrees, with ease. Protractors come in both analogue and digital variants that offer a wide range of applications in mechanics, engineering and geometry.

Why protractors?

Protractors and digital protractors give accurate measurements of angles that aid in the drawing and designing process to ensure accurate plans are created.

When are protractors used?

Different types of protractors are used in different scenarios to find the correct angle for required. Standard geometry protractors are used for drawing 2D angles on paper, digital versions have more practical three-dimensional applications.

Protractor types

There are 3 main types of protractors that provide excellent angle measurement in a wide variety of applications:

• Semi-Circular Protractor   -   Also known as a geometry protractor has two sets of scales graduated up to 180° in opposite directions enabling angles to be read from two directions.

• Bevel Protractor   -   Has a swinging arm that can rotate up to 360° enabling angles to be read from two directions.

• Digital Protractors   -   Also called an angle finder, these also feature a swinging arm like the bevel protractor along with a digital display that provides an accurate readout of what angle the arm has moved to.

Considerations when choosing a protractor

• Range   -   Protractors have a range of measurement either between 0 and 180 degrees or between 0 and 360 degrees, choosing the protractor range that suits your application can ensure you get accurate measurements.
• Accuracy   -   The accuracy of a protractor can ensure that accurate measurements can be made so that even the slightest mistake cannot lead to bigger consequences.
• Display   -   Geometry protractors have multiple measurements printed directly on to aid the process of finding an angle. While a digital protractor will have an electronic display that can show a greater number of decimal points for increased accuracy.

FAQs

Why are there two scales on a protractor?

The two scales on a protractor make it easy to measure angles facing different ways without the need to move the protractor. This helps to increase the accuracy of measurement.

How accurate are digital protractors?

Digital protractors are extremely accurate. There may be small variations in the accuracy of different models, but many can have +/- 0.1 degrees of accuracy.