tool

A tool or device is a piece of equipment which typically provides a mechanical advantage in accomplishing a physical task. The most basic tools are simple machines. For example, a crowbar simply functions as a lever. The further out from the pivot point, the more force is transmitted along the lever. When particularly intended for domestic use, a tool is often called a utensil.

Philosophers once thought that only humans used tools, and often defined humans as tool-using animals. But observation has confirmed that monkeys, apes and other animals, mostly primates, but also some birds (ravens, for instance), and sea otters can use tools as well. Later, philosophers thought that only humans had the ability to make tools, until zoologists observed birds^[1] and monkeys^[2][3][4] making tools.

Most anthropologists believe that the use of tools was an important step in the evolution of mankind. Humans evolved an opposable thumb - useful in holding tools - and increased dramatically in intelligence, which aided in the use of tools.^[5]

Some tools can also serve as weapons, such as a hammer or a knife. Similarly, people can use weapons, such as explosives, as tools.

Tools can also be largely cognitive, such as written language. Non-physical entities such as process (improvement or reengineering), information architecture, creativity, and learning itself are all invaluable tools used by humans for individual and collective benefit.

Functions of tools

Many tools or groups of tools serve to perform one or more of a set of basic operations, such as:

• Cutting (knife, scythe, sickle, etc...)
• Concentrating force (hammer, maul, screwdriver, whip, writing implements, etc...)
• Guiding (set square, algorithm, straight edge, etc...)
• Protecting
• Seizing and holding (pliers, glove, wrench, etc...)

Tool substitution

Often, by design or coincidence, a tool may share key functional attributes with one or more other tools. In this case, some tools can substitute for other tools, either as a make-shift solution or as a matter of practical efficiency. "One tool does it all" is a motto of some importance for workers who cannot practically carry every specialized tool to the location of every work task. Tool substitution may be divided broadly into two classes: substitution "by-design", or "multi-purpose" use, and substitution as make-shift. In many cases, the designed secondary functions of tools are not widely known. As an example of the former, many wood-cutting hand saws integrate a carpenter's square by incorporating a specially shaped handle which allows 90° and 45° angles to be marked by aligning the appropriate part of the handle with an edge and scribing along the back edge of the saw. The latter is illustrated by the saying "All tools can be used as hammers." Nearly all tools can be repurposed to function as a hammer, even though very few tools are intentionally designed for it.

Multi-use tools

• A Multitool is a hand tool that incorporates several tools into a single, portable device.
• Lineman's pliers incorporate a gripper and cutter, and are commonly used secondarily as a hammer.
• Hand saws often incorporate the functionality of the carpenter's square in the right-angle between the blade's dull edge and the saw's handle.

History

Main article: History of technology

Use of tools started at the beginning of the Stone Age. Humans have made knives, among the oldest tools, since that time.

Mechanical devices, though known to Alexandrian Greeks, experienced a major expansion in their use in the Middle Ages with the systematic employment of new energy sources: water (waterwheels) and wind (windmills).

Machine tools occasioned a surge in producing new tools in the industrial revolution. Advocates of nanotechnology expect a similar surge as tools become microscopic in size.^[6][7]