Daily Archives: September 15, 2016
iPhoneOgraphy – 15 Sep 2016 (Day 259/366)
A wrench (or spanner outside of North America) 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 (excluding Canada), 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 (e.g. tap wrench and pipe wrench), or may be used for a monkey wrench – an adjustable spanner.
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. (These pins or tabs fit into the holes or notches cut into the object to be turned.) 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.
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 to narrowing or widening the jaws, including patented monkey wrenches.
An adjustable wrench (US) or adjustable spanner(UK) is a wrench with a “jaw” of adjustable width, allowing it to be used with different sizes of fastener head (nut, bolt, etc.) rather than just one fastener, as with a conventional fixed spanner.
In many European as well as Middle Eastern countries (e.g. France, Germany, Portugal, Spain, Italy, Syria, Lebanon, Turkey, etc.) the adjustable wrench is called an “English key” as it was first invented in 1842 by the English engineer Richard Clyburn. Another English engineer, Edwin Beard Budding, is also credited with the invention. Improvements followed: on 22 September 1885 Enoch Harris received US patent 326868 for his spanner that permitted both the jaw width and the angle of the handles to be adjusted and locked. Other countries, like Denmark, Poland and Israel, refer to it as a “Swedish key” as its invention has been attributed to the Swedish inventor Johan Petter Johansson, who in 1892 received a patent for an improved design of the adjustable spanner that is still used today. Johansson’s spanner was a further development of Clyburn’s original “screw spanner”. In some countries (e.g. Czech Republic, Egypt, Greece, Hungary, Serbia, Iran, Slovakia, Slovenia, Poland, Romania, Bulgaria) it is called “French key” (in Poland, “Swedish” or “French” key depending on type). In Canada and the USA, the tool is known as a Crescent wrench or an adjustable wrench.
There are many forms of adjustable spanners, from the taper locking spanners which needed a hammer to set the movable jaw to the size of the nut, to the modern screw adjusted spanner. Some adjustable spanners automatically adjust to the size of the nut. Simpler models use a serrated edge to lock the movable jaw to size, while more sophisticated versions are digital types that use sheets or feelers to set the size.
The fixed jaw can withstand bending stress far better than can the movable jaw, because the latter is supported only by the flat surfaces on either side of the guide slot, not the full thickness of the tool. The tool is therefore usually angled so that the movable jaw’s area of contact is closer to the body of the tool, which means less bending stress.
Monkey wrenches are another type of adjustable spanner with a long history; the origin of the name is unclear.
The type of straight adjustable spanner with jaws at right angles to the handle shown here as an “English Key” is mainly called a “King Dick” spanner in the United Kingdom because of a popular British brand of small, handy and reliable adjustable spanner used throughout the 1900s and used in great numbers during World War II.