Socket set with ratchet
A socket wrench is a type of wrench or spanner that has a socket attached at one end, usually used to turn a fastener.
The most prevalent form is the ratcheting socket wrench, often informally called a ratchet.
A ratcheting socket wrench is the device within a hand tool in which a metal handle is attached to a ratcheting mechanism, which attaches to a socket.
Pulled or pushed in one direction, the ratchet loosens or tightens the bolt or nut attached to the socket.
Turned the other direction, the ratchet does not turn the socket but allows the ratchet handle to be re-positioned for another turn while staying attached to the bolt or nut.
Other common methods of driving socket wrenches include pneumatic impact wrenches, hydraulic torque wrenches, torque multipliers and breaker bars.
Socket wrenches are most commonly hexagonal, or more commonly referred to as “6-point” in lay terms.
This wide range of square drive sizes provides for a wide variety of socket types and sizes to suit small to very large nuts and bolts.
Some common hand ratchets employ a quick release button on their top for quick socket release of smaller sockets.The tool chosen to drive the socket wrench ultimately supplies the mechanical advantage needed by the user to provide the torque needed to loosen or tighten the fastener as may be required.
A socket is typically a cylinder which has a female six– or twelve-point recessed opening sized to fit over the common male hexagonal head of a bolt or nut fastener.
The opposite end of the socket wrench has a standardized (ANSI B107, ISO, or other consensus standard) square recess to accept the socket wrench’s drive size.
The principal advantage of interchangeable sockets is that, instead of a separate wrench for each of the many different fastener sizes and types, only separate sockets are needed for each size and type.
Sockets often come as a “socket set” with many different sizes or types of sockets to fit the heads of different-sized fasteners.
A ratchet of the “set size” is often included with the socket set.
First ratcheting socket wrench, made by J.J. Richardson, 1863.
Socket wrench types
A non-ratcheting socket wrench where the socket is attached permanently to the end of a L-shaped, or X-shaped bar.
They are designed as special use socket wrenches for loosening and tightening lug nuts on automobile or truck wheels.
A screwdriver-type handle for hand turning with a built-in female socket at the end of either metric or fractional inch sizes.
flex-head socket wrench
ratcheting socket wrench
The most common type of socket wrench.
The advantages of the system of a ratchet wrench with indexable sockets are speed of wrenching (it is much faster than a conventional wrench, especially in repetitive bolt-on or bolt-off usage) and efficiency of tooling cost and portability (it is much more efficient than a set of non-ratcheting wrenches, with every size head having its own handle).
Ratchets with a knurled palm sized circular ratchet handle with reversible socket attachment useful for rapidly loosening or tightening a bolt or nut.
Breaker bars are usually slightly longer and built more sturdily than a standard ratchet handle and often have a swiveling head that attaches to the socket.
Breaker bars are used with a socket of the correct size and type to “break loose” very tight fasteners because their additional length and strength allows the same amount of force to generate significantly more torque than a standard length socket wrench.
The use of a breaker bar also prevents potential damage to the ratcheting mechanism of a socket wrench.
Once the fastener is “broken loose,” it can be turned with a socket wrench or by hand.
Usually non-ratcheting, made to attach to standard sockets.
A fixed drive where the head spins relative to the handle spinning, with the handle having a drive attachment where a ratchet or other socket wrench can be attached.
There are also power tool versions of “air” (pneumatic) ratchets which use compressed air power to drive air powered socket wrenches which tighten or loosen nuts or bolts.
There are two main types of socket wrenches: impact sockets and hand sockets.
Other specialized screw heads that are often installed or removed with screwdriver type handles and appropriate type tip have socket varieties that fit the various screw head types and a can be attached to a socket wrench.
Conversely, for low torque situations, a “socket spinner” screwdriver handle with a socket wrench type fitting on one end can be attached to many different types of sockets, bit drivers and extensions.
A socket wrench, with the correct type of socket, can be used to loosen or tighten a large variety of fasteners with lower cost, greater ease and often more torque than can be applied with a screwdriver handle.
A common use of these different “screw” head type sockets is to attach to power versions of the socket wrenches (impact sockets) which allow the fasteners to be loosened or tightened much faster and more powerfully than can be done by hand.
This versatility is the main purpose of the 12-point shape found in common sockets, but is essential when working with 12-point bolt and nut heads.
Specialized “wobble” or swivel sockets are made, that have a separate socket head and socket wrench connection.
This allows the socket to wobble or swivel over a limited range, independent of the socket wrench or tool position, when it is attached to the bolt or nut.
These “wobble/swivel” sockets, with their typical ball and socket joint swivel attachments, are made in a wide variety of types and sizes including deep, shallow, impact, triple square.
Many socket types and sizes are available with a universal joint between the socket and the ratchet attachment for tightening or loosening fasteners which are not easy to access with the socket wrench, plus standard socket arrangement.
Also available are short universal joint extensions that allow any socket to be attached to a ratchet at with a universal joint between the two.
Even if the socket attached to the impact wrench does not turn, it is still subjected to successive shock blows by the impact wrench’s internal hammer(s).
Impact wrenches are hard on the sockets since the sockets in use also get hammered.
Regular chrome plated “hand sockets” like those commonly included with hand ratchet wrench tool sets are not suitable for this kind of high load impact application.
For more flexibility, many impact sockets are made with swivel type socket—socket wrench attachment geometry.
Pass-through sockets and ratchets
Pass-through sockets and ratchets are built for 1/4″, 3/8″ and 1/2″ sets in both SAE and metric sizes.
Extension Grip Collars are collars with indents that fit on the back of most extensions preventing it from easily rolling away and allow one to easily grip extension and finger tighten or loosen nuts and bolts by turning extension + socket with or without ratchet.
Size adapters allow sockets of one drive size to be used with ratchets of another drive size.
ASME B107 – specification for Socket Wrenches, Handles, and Attachments
Source: Socket wrench