Circular saw

A circular saw is a tool for cutting many materials such as wood, masonry, plastic, or metal and may be hand-held or mounted to a machine.

[1] There is evidence for the prehistorical use of circular saws by people of Indus Valley Civilization during the Bronze Age.

The rotary nature of the circular saw requires more power to operate but cuts faster because the teeth are in constant motion.

Sawmills first used smaller diameter circular saws to resaw dimension lumber such as lath and wall studs and for edging boards.

The cubic meter and Cord (unit) are common measurements of standing timber (by estimation) or rough logs.

In the nineteenth and early twentieth centuries, farmers would supply householders in town with cordwood, which would then be re-sawn and split to a length and circumference suitable for woodburning heaters and ranges.

Almost all these devices were designed to accept 16-inch (410 mm) sticks, conveniently a piece of cordwood cut into three equal lengths.

Most cordwood saws consist of a frame, blade, mandrel, cradle, and power source.

Certain cordwood saws are run from a belt from a farm tractor power takeoff pulley.

Others, mounted on a tractor's three-point hitch, connect to the rear power takeoff shaft.

Self-powered models are equipped with small gasoline engines or even large electric motors as power sources.

They were used to cut smaller wood into firewood in an era when hand powered saws were the only other option.

In a worm-drive saw, the blade is driven by a perpendicularly mounted motor using worm gears, which give higher torque.

The saw blades used are quite large in diameter and operate at low rotational speeds, and linear feeds.

There are three common types of blades used in circular saws; solid-tooth, segmental tooth, and the carbide inserted-tooth.