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Wrench

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A wrench, also known as a spanner in many countries, is a fundamental mechanical tool.

Gedore No. 7 combination wrenches 6–19 mm
Gedore No. 7 combination wrenches 6–19 mm

It is designed to provide grip and mechanical advantage. This advantage allows a user to apply torque to an object. Torque is the twisting force used to rotate something. Most often, wrenches are used on rotary fasteners like nuts and bolts. They can either tighten these fasteners or prevent them from turning.

AdjustableWrenchWhiteBackground
AdjustableWrenchWhiteBackground

This tool is essential for engineering, automotive repair, and home maintenance.

The mechanism of a wrench relies on the relationship between the tool and the fastener. When the jaws of a wrench grip the faces of a nut, the user applies force to the handle. This force creates torque at the point of contact. The design of the wrench determines how much contact is made with the fastener. For example, an open-end wrench uses a U-shaped opening to grip two opposite sides.

Kluc ockoplochy
Kluc ockoplochy

A ring spanner provides an enclosed loop for more complete contact. Some ring spanners feature a 12-point design. This provides more engagement points than a 6-point design. While 12-point wrenches work on more angles, they can sometimes cause damage to 6-point bolts. This happens because they provide less contact space per point.

Wrenches are categorized by their specific shapes and functions. Common types include the open-end wrench and the ring spanner. A combination spanner is a double-ended tool. It features an open end on one side and a ring end on the other. Both ends typically fit the same size bolt. Another common type is the ratcheting ring spanner. This tool uses a ratcheting mechanism to allow continuous turning.

Point tailed ratchet spanner
Point tailed ratchet spanner

This allows the user to turn a fastener without removing the tool from the bolt. Other specialized versions include the Saltus wrench, which has a permanently affixed socket. There are also crow's foot wrenches. These are used when space is tight or when torque must be measured precisely.

Crow's foot wrench
Crow's foot wrench

The history of these tools stretches back many centuries. Historians have identified wrenches and similar devices as far back as the 15th century. These early tools were used for items like suits of armor and pipe clamps. The word "wrench" comes from the Old English word "wrench," meaning a turning or twisting. The term "spanner" has a different origin. It entered use in the 1630s to describe a tool for winding the spring of a wheel-lock firearm.

Monogramist HLF Wheel-lock gun 13
Monogramist HLF Wheel-lock gun 13

In the late 18th and early 19th centuries, adjustable coach wrenches were exported from England to North America. By the mid-19th century, inventors began patenting wrenches that used screws to adjust the jaw width.

Material science plays a major role in how modern wrenches are manufactured. High-quality wrenches are often made from chromium-vanadium alloy tool steels. This specific alloy provides the necessary strength and durability. Many of these tools are also drop-forged to increase their toughness. To prevent rust and make them easier to clean, they are frequently chrome-plated.

Socket wrench and sockets
Socket wrench and sockets

This protection is vital for tools used in harsh environments. Different specialized wrenches serve specific industrial needs. For instance, a striking wrench is thick and short. It is designed to be hit with a hammer to impart great force. This is useful for large, stuck fasteners or for calculating precise torque through preload.

There are many specialized examples of wrenches used in different trades. The adjustable end wrench is one of the most common tools in use today.

AdjustableWrenchWhiteBackground
AdjustableWrenchWhiteBackground

A well-known brand name for this is the Crescent wrench. For plumbing, workers often use a pipe wrench, sometimes called a Stillson wrench. These have hardened, serrated jaws to grip soft iron pipes securely.

Rohrschluessel
Rohrschluessel

In automotive work, socket wrenches are very common. A socket is a closed cylinder that fits over a bolt head. These can be used with different drive tools like a ratchet handle. Another common tool is the Allen wrench, which is L-shaped. These are used to turn bolts with hexagonal recesses.

Allen wrench and screw (PSF)
Allen wrench and screw (PSF)

Wrenches are connected to many broader concepts in physics and language. The concept of mechanical advantage is central to how they function. By using a longer handle, a user can increase the torque applied to a fastener. This allows humans to move objects that would otherwise be too tight to turn. Even our language reflects these tools. In the United States, the phrase "throwing a monkey wrench into the works" is used as slang. It describes an unexpected obstacle that stops a process. This shows how much influence these simple mechanical tools have on our daily lives and how we communicate.

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🖼️ Images & Media (52)
File:Gedore No. 7 combination wrenches 6–19 mm.jpg
Gedore No. 7 combination wrenches 6–19 mm.jpg
File:Monogramist HLF Wheel-lock gun 13.jpg
Monogramist HLF Wheel-lock gun 13.jpg
File:Clé plate.jpg
Clé plate.jpg
File:Kluc ockovy vysunuty.jpg
Kluc ockovy vysunuty.jpg
File:Kluc ockoplochy.jpg
Kluc ockoplochy.jpg
File:Bremsleitungsschluessel.JPG
Bremsleitungsschluessel.JPG
File:Point tailed ratchet spanner.jpg
Point tailed ratchet spanner.jpg
File:Craftsman Saltus wrenches.jpg
Craftsman Saltus wrenches.jpg
File:Spanner wrenches various kinds from Colvin and Stanley 1910 p64.png
Spanner wrenches various kinds from...
File:Kluc vidlicovy uderovy.jpg
Kluc vidlicovy uderovy.jpg
File:AdjustableWrenchWhiteBackground.jpg
AdjustableWrenchWhiteBackground.jpg
File:Self-adjusting wrench.jpg
Self-adjusting wrench.jpg

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