How a circular saw works?

Using a torque force, these clever cutting tools make light work of wood

Circular saws rely on providing a large ‘torque’ in the centre of a hole in the blade. As a force is applied to one side of the hole, a torque force is created much like when using a spanner on a nut, although signiﬁ cantly faster. When cutting through an object such as wood, the circular saw is placed ﬂ at with the saw pointing down. The wood is clamped in place. By slowly moving the blade through the wood it will produce a clean cut. There are several types of circular saw, most spinning at up to 3,500 rotations per minute (rpm) to make a clean cut through an object. Some connect the motor directly to the saw for a one-to-one speed ratio. Others use a combination of large and small cogs to alter the revolution of the saw and ultimately the speed. For example, by attaching a large gear cog to a smaller one on the blade, usually at a ratio of two to one, a motor turning at 1,750 rpm will actually move the blade at 3,500 rpm

Gullet

The teeth are designed to remove any material shed from the object it is cutting. This allows for a clean cut with no rough edges.

Double gear

In this double gear system, a large cog is powering the smaller cog by applying a large torque force, which increases the number of revolutions.

Blade hole

Although most saws use a round hole, some use a diamond shaped hole for a higher torque force.

Tip

Carbide is a compound of carbon and iron, which is sometimes used to make the teeth. It is stronger and longer lasting than steel.

Teeth

For each revolution, the saw will cut further and more swiftly into an object if there are more teeth

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