Technical drawing tools

The ruler

The graduated ruler is the most common tool used for making straight lines and to measure distances. It has a bevelled edge with the measurements marked in millimetres.

Triangular set square

There are two types of set squares and they are named according to the angles present on each.

It’s an isosceles triangle. Two sides make a 90 º angle and its hypotenuse forms a 45 º angle with each of the other two sides. 45 º Triangular set square

It’s is a scalene triangle. The two sides make a 90 º angle, the hypotenuse makes a 60 º angle with one of the sides and a 30 º angle with the other. 60 º Triangular set square

Mechanical pencil

It is a plastic or metal tool that has an inner tube that holds a graphite lead. Mechanical pencils are designed to provide lines of constant thickness without requiring sharpening.

Stylograph This is a tool we use for ink drawings.

The protractor A protractor is used to transfer and measure angles. The units of measurement utilized are usually degrees.

The compass This tool is used to make arched lines and circles.

ACTIVITY

What is the function of each of these tools? Set square Mechanical pencil Stylograph Protractor RulerCompass

We use it for making straight lines. We use it to measure distances. We use it to transfer and measure angles We use it for ink drawings We use it to make arched lines We use it to make lines of constant thickness We use it to draw parallel and perpendicular lines What is the function of each of these tools?

SOLUTION What is the function of each of these tools ?

We use for making straight lines. We use to measure distances. Ruler What is the function of each of these tools ?

We use to transfer and measure angles Protractor We use to make lines of constant thickness Mechanical pencil

Set square We use to draw parallel and perpendicular lines We use to make arched lines Compass We use for ink drawings Stylograph