What kinds of wrenches are there?
Wrenches are made in various shapes and sizes and are used for gripping, fastening, turning, tightening and loosening things like pipes, pipe fittings, nuts and bolts. There are basically two major kinds of wrenches:
Wrenches may be adjustable to fit different sized pipes, nuts and bolts or may be a fixed size.
- context Pipe wrenches used in plumbing for gripping round (cylindrical) things.
- context General-use wrenches used on nuts and bolts that have flat, parallel surfaces; e.g., square or hexagonal (hex).
What are some examples of adjustable wrenches?
Adjustable wrenches include:
- context Pipe wrenches.
- context Crescent™ wrenches which have adjustable jaws set at a 30-degree angle from the handle. Although Crescent is a trade name, it is widely used to refer to any regular adjustable wrench with an angled jaw, regardless of who manufactured it.
- context Monkey wrenches which have their adjustable head at a 90-degree angle from the handle.
What are some examples of fixed-size wrenches?
Fixed-sized wrenches include:
Fixed wrenches fit single, specific sizes. Metric wrench sizes are expressed as whole numbers (e.g., 8, 10, 14, 32) that correspond to the sizes in millimetres. Non-metric sizes used widely in the U.S. are also called S.A.E (Society of Automotive Engineers) sizes and are expressed as fractions of an inch; e.g., 1/4, 1/2, 3/4, 1 1/4. Since both metric and S.A.E. fasteners (nuts, bolts, etc.) are used in Canada, users must select the correct type and size of wrench to prevent injuries and damage to equipment in case of slippage when force is applied to the wrench.
- context Open-ended wrenches that have "jaws" with parallel sides or tines that fit snugly on nuts and bolts.
- context Closed-end or box wrenches that have a loop at the end with notches on the inside that allow the wrench to fit either square or hex nuts or both (depending on the number of notches or points).
- context Combination wrenches that have both an open end and a closed end on either end of the wrench; usually they fit the same size nut or bolt.
- context Socket wrenches are similar to closed-end wrenches except they are cylindrical in shape. They can fit over a nut in a recessed hole that would be inaccessible with open- or closed-ended wrenches. These wrenches have an offset handle at right angles to the nut being tightened or loosened. Usually, the handle is a ratchet-type handle that allows the user to turn the socket continuously in one direction by moving the handle back and forth without having to take the socket off the nut.
- context Torque wrenches, one type of socket wrench, have a built-in spring-loaded indicator that shows how much torque is being applied (i.e., shows how hard the nut is being tightened).
- context Nut drivers, another type of socket wrench, are sockets that can be snapped on or permanently fixed to a screwdriver-type handle.
- context Allen wrenches or Allen keys are hexagon-shaped (six-sided) metal shafts that are bent into an L-shape for leverage. Hex drivers are "straight Allen wrenches" that have a screwdriver-type handle. These are different from the other wrenches since they fit inside a recessed hexagonal hole in screw heads instead of around a nut or bolt.