Types of Wrench/Spanner

Common wrenches

Double open-end wrench or open-ended spannerOpen-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. The ends are generally oriented at an angle of around 30 degrees to the longitudinal axis of the handle. This allows a greater range of movement in enclosed spaces by flipping the wrench over.

Box-end wrench, or Box spanner, or Ring spanner: a one-piece wrench with an enclosed opening that grips the faces of the bolt or nut. The recess is generally a six-point or twelve-point opening for use with nuts or bolt heads with a hexagonal shape. The twelve-point fits onto the fastening at twice as many angles, an advantage where swing is limited. Eight-point wrenches are also made for square shaped nuts and bolt heads. Box-ends are also often double-ended.

Double Handled Tap Wrench, 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-end 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 (commonley known as a shifter): 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: an old type of adjustable end wrench with a straight handle and smooth jaws, these are also known in the UK as 'gas grips'.
• Crescent® wrench: the brand name of an improved version of the adjustable end wrench developed by the Crescent Tool and Horseshoe Company. Often 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 addition, 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).

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.

Saltus wrench: similar in concept to a socket wrench. A Saltus wrench features a socket permanently affixed to a handle; sockets are not interchangeable as with a socket wrench. The socket often rotates around the handle to allow the user to access a fastener from a variety of angles. Commonly a Saltus wrench is part of a double-ended wrench, with an open-end type head on the opposide side from the socket head.

A mole wrench, also known as a mole grip, is not a wrench but a type of self-locking pliers

From Pocket Wikipedia, http://www.free-soft.ro/pocket-wikipedia/