Home > Wrench

In American English, wrench is the standard term, while 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 British English, spanner is the standard term.

Wrenches are generally one of two types: the double–handled wrench (see image at right) and the end wrench; with the end wrench, by far, the most common. Hinged tools, such as pliers or tongs, are not generally considered wrenches.

1 Common wrenches

• Open-end wrench, or Open-ended spanner: a one-piece wrench with a U-shaped opening that grips two opposite faces of the bolt or nut. This wrench is often double ended, with a different sized opening at each end.
• Box-end wrench, or Box spanner, or Ring spanner: a one-piece wrench with a enclosed opening that grips the faces of the bolt or nut. The recess is generally a six-point or twelve-point opening. The six-point is used for nuts or bolt heads with a hexagonal shape. The twelve-point can be used with either square or hex shaped nuts and bolt heads but is not as durable. Box-ends are also often double-ended.
• Combination wrench, or Combination spanner: a double-ended tool with one end being like an open-end wrench or open-ended spanner, and the other end being like a box wrench or ring spanner. Both ends generally fit the same size bolt.
• Flare-nut wrench, or Tube wrench: used for gripping the nuts on the ends of tubes. The design is similar to a box–end wrench but with an opening to allow the wrench to fit over the tube.
• Adjustable end wrench, or Adjustable spanner, or Shifting spanner: an open-ended wrench with adjustable (usually smooth) jaws, also sometimes called by the original patent holder's brand name as a Crescent® Wrench (Crescent Tool and Horseshoe Company).

• Monkey wrench: the original adjustable end wrench with a straight handle and smooth jaws.
• Crescent® wrench: the brand name of an improved version of the adjustable end wrench (see the photo at right) developed by the Crescent Tool and Horseshoe Company. Often, incorrectly, used as a generic term.
• Pipe wrench: an adjustable end wrench with self-tightening properties and hard serrated jaws that securely grip soft iron pipe and pipe fittings. Sometimes known by the original patent holder's brand name as a Stillson® Wrench.

• Socket wrench: a hollow cylinder that fits over one end of a nut or bolt head—may include a handle but usually used with various drive tools. It generally has either a six–point or twelve–point recess, may be shallow or deep, and may have a built-in universal joint. In additon face driving sockets are available. These are more durable still, and have the ability to drive a range of hexagonal head sizes, with less risk of damaging the nut or bolt head than traditional "corner" drivers. The drive handles generally used are:

a break–over (or hinged) handle.

a ratchet handle (contains a mechanism which allows the socket to be turned without removing it from the nut or bolt).

a speed handle (sometimes called a crank handle).

a screwdriver handle (for use of the socket as a nutdriver).

Sockets are often sold as a set containing a collection of sockets of various sizes and associated drive tools; usually including, as a minimum, extensions, a ratchet driver, and a universal joint. Sockets are also used with various power tools.

• Crowfoot socket wrench: a type of socket designed to fit some of the same drive handles as the regular socket but non-cylindrical in shape. The ends are the same as those found on the open-end, box-end, or the flare-nut wrenches. These sockets use for use where space restrictions preclude the use of a regular socket. Their principle use is with torque wrenches.