Wrench
A wrench or spanner is a tool used to provide grip and mechanical advantage in applying torque to turn objects—usually rotary fasteners, such as nuts and bolts—or keep them from turning.
In Commonwealth English, spanner is the standard term. The most common shapes are called open-ended spanner and ring spanner. The term wrench is generally used for tools that turn non-fastening devices, or may be used for a monkey wrench - an adjustable pipe wrench.
In North American English, wrench is the standard term. The most common shapes are called open-end wrench and box-end wrench. In American English, spanner refers to a specialized wrench with a series of pins or tabs around the circumference.. In American commerce, such a wrench may be called a spanner wrench to distinguish it from the British sense of spanner.
Higher quality wrenches are typically made from chromium-vanadium alloy tool steels and are often drop-forged. They are frequently chrome-plated to resist corrosion and for ease of cleaning.
Hinged tools, such as pliers or tongs, are not generally considered wrenches in English, but exceptions are the plumber wrench and Mole wrench.
The word can also be used in slang to describe an unexpected obstacle, for example, "He threw a spanner in the works".
Etymology
'Wrench' is derived from Middle English wrench, from Old English wrenċ, from Proto-Germanic *wrankiz. First used in 1790.'Spanner' came into use in the 1630s, referring to the tool for winding the spring of a wheel-lock firearm. From German Spanner, from spannen , from Proto-Germanic *spannan, from PIE root *pen-.
History
Wrenches and applications using wrenches or devices that needed wrenches, such as pipe clamps and suits of armor, have been noted by historians as far back as the 15th century. Adjustable coach wrenches for the odd-sized nuts of wagon wheels were manufactured in England and exported to North America in the late eighteenth and early nineteenth centuries. The mid 19th century began to see patented wrenches which used a screw for narrowing and widening the jaws, including patented monkey wrenches.Most box end wrenches are sold as 12-point because 12-point wrenches fit over both 12-point and 6-point bolts. 12-point wrenches also offer a higher number of engagement points over 6-point. However, 12-point wrenches have been known to round off 6-point bolts as they provide less contact space.
Types
Other types of keys
These types of keys are not emically classified as wrenches by English speakers, but they are etically similar in function to wrenches.| American name | British/Commonwealth name | Description | Group | |
| chuck key | A key used to tighten or loosen a chuck. | household/industrial | ||
| church key, bottle opener | church key, bottle opener | A key used to remove bottle caps or to pierce can lids. | household | |
| paint can opener | A key used to open the lids of paint cans. Its upturned edge helps to apply a levering motion to the crimped lip of the can lid. | household | ||
| sillcock key, loose key, tap key | A key used to open or close sillcock valves. Many are designed the same way as a :File:Kreuzschlüssel.jpg|spider-type lug wrench, with four common sizes built into one portable tool. | household | ||
| window crank | A socket-like key slipped over the splined shaft that operates the opening and closing of some types of window. | household | ||
| sardine tin key | A key used in opening the lids of canned fish or canned meat. A tab on the metal lid fits into the slot in the shaft of the key and the lid is wound onto the key, tearing it away from the can. | household | ||
| dental key | A key formerly used in dentistry for leverage in pulling teeth | historical |