Socket wrench and ratchet

How it works

The socket fits over the fastener on its outside faces and is turned from the other end through a square drive. The handle is a separate part that clips onto the drive square, so a single handle serves many sockets. In Richardson’s 1863 patent all the sockets are the same size externally and differ only in the size of the square opening, so one wrench fits nuts of different sizes.

In a ratchet handle a toothed wheel is engaged by a spring-loaded pawl. The nut is turned by an oscillating movement without taking the wrench off the nut: the pawl catches the teeth when the handle moves one way and slips over them when it moves the other. Richardson’s patent used two pawls, one for pulling and one for pushing, with a spring keeping both engaged.

The angle the handle must swing before the next tooth engages sets how little room the ratchet needs. The TEKTON flex-head ratchet is described by its maker as having a 90-tooth gear and a 4 degree swing arc; the maker adds that the single pawl keeps nine teeth engaged at all times.

Anatomy

Socket: A hollow steel body with a drive square at one end and a polygonal opening for the fastener at the other. Modern sockets carry detent grooves for the retaining ball of the drive tool.
Opening (6-point or 12-point): A hexagon (6-point) or double hexagon (12-point). Early sockets were also made with square (4-point) and double-square (8-point) openings.
Drive square: The square hole at the other end of the socket, which takes the square tang of the handle. Common sizes include 1/4, 3/8, 1/2 and 3/4 inch.
Ratchet head: Houses the toothed gear and pawl; a lever or knob reverses the direction. The pivot is the drive tang.
Handle: Straight, flat or oval; on a flex-head ratchet the head swings through 180 degrees and locks at detent positions.

Variants

Ratchet handle: The common drive tool, a reversible ratchet with a head that engages the socket drive square. TEKTON cites ASME B107.110 for the category “handles, ratchet, reversible.”
Flex-head or hinge handle: A handle with a head that swivels. Alloy Artifacts reports that Plomb and P&C were the first to introduce flex-head drive handles for sockets in 1926, which Plomb’s catalogs called hinge handles.
Shallow, semi-deep and deep sockets: Different socket lengths for different clearance and thread lengths; TEKTON offers each in 6-point and 12-point forms.
Impact socket: A heavier socket for impact drivers; TEKTON lists a 3/4 inch drive 6-point impact socket line.
Breaker bar, extension, universal joint, speed handle: Other drive tools that fit the same square. Alloy Artifacts lists breaker bars, speeders and extensions among Snap-on’s early drive tools.
Bridge ratchet wrench: A large ratchet wrench for construction work; Alloy Artifacts says the Lowell Wrench Company is believed to have originated this type.

Specifications

Drive size · in: 1/4, 3/8, 1/2, 3/4 (hand tools); 1 in. also in industrial setsAlloy Artifacts reports Snap-on’s first sockets in 1920 were 1/2 inch drive only, with 5/8 added in 1923, 7/8 around 1924, 9/32 in 1925 and 3/8 in 1928.
Points · 6 or 12: 6 and 12Double-hex (12-point) and double-square (8-point) broachings were introduced by Snap-on in 1927, according to Alloy Artifacts.
Ratchet teeth and swing arc · teeth; degrees: One maker’s flex-head ratchet has 90 teeth and a 4 degree swing arc; no standard value has been sourced.
Proof torque · ft-lb or N·m: Specified by ASME B107.110 by drive size and tool category; the values have not been read here.

Made to

ASME B107.110
ASME B107.4
ISO 1174

Safety and care

Safety

OSHA states that the greatest hazards of hand tools result from misuse and improper maintenance, and that employers may not issue or permit the use of unsafe hand tools.

Tips

Use a 6-point socket for the best fit, a 12-point for access
TEKTON states that its 6-point opening provides an exact fit and maximum contact for hex fasteners, and that its 12-point opening gives more access positions for different fasteners. Both have radiused corners that load the flats of the fastener rather than its corners, which the maker says prevents round-off.1 2
Read the ratchet by its tooth count
A ratchet’s swing arc is the handle travel needed before the pawl can engage the next tooth, so a finer gear works in less room. TEKTON describes a 90-tooth gear as giving a 4 degree swing arc.1
Detent grooves hold the socket on the drive
TEKTON’s sockets have four detent grooves in the drive square hole that engage the retaining ball of the drive tool, so the socket stays on the handle or extension until pulled off.1
Set a flex head at a detent angle to reach around obstacles
TEKTON’s flex-head ratchet sweeps through 180 degrees and snaps to nine detent angles, where a spring-actuated pawl holds the head in position.1
Handle length is measured from the drive tang
TEKTON names its ratchets and breaker bars by effective working length, measured from the center of the drive tang to the end of the handle, which is the distance over which the hand’s force acts.1
Sockets are interchangeable across handles by design
Snap-on’s founding idea in 1920, according to Alloy Artifacts, was the superiority of interchangeable socket tools over fixed (“tight”) socket wrenches. A set of five handles and ten sockets was the first product; Richardson’s 1863 patent already used several sockets of one outside size with a single handle.1 2 3

History

Earliest documented

16 June 1863 (documentary)

Woodstock, Vermont

J. J. Richardson of Woodstock, Vermont, was granted US Patent 38,914 on 16 June 1863 for a “new and improved ratchet-wrench.” It combines a ratchet, two pawls, a spring and a removable socket so that a nut can be turned by an oscillating movement without taking the wrench off it and one wrench can serve different sizes of nuts. Its stated object is use where space is restricted.1

The ratchet socket wrench was designed for restricted space. Richardson’s 1863 patent states its object: a wrench for cases where an ordinary wrench cannot be used, or has to be taken off the nut and re-applied at every turn, because space is restricted. It also states the second object, that the same wrench be capable of being applied to different sized nuts, and it meets it with several interchangeable sockets of one outside size and different square openings. The patent describes the whole arrangement as extremely simple, with no parts liable to be deranged by use.

The first generation of ratchet wrenches grew slowly. The Moore patent of 1864 is a lever-operated ratchet with detents, and Alloy Artifacts reports that the Lowell Wrench Company, founded in 1869 to make a ratchet handle based on Moore’s patent, is believed to have originated large ratchet wrenches for construction work. Which of the two Vermont inventors made the first working ratchet is disputed: Richardson holds the earlier patent, while a forum post cites an 1880 court case to say a working Moore ratchet existed in 1859. That decision has not been read here.

The decisive change came with the automobile. Alloy Artifacts reports that in the early 1920s heavy-wall turned and broached sockets were rapidly replacing the older pressed-steel sockets, and that interchangeable socket sets from Blackhawk (1919) and Snap-on (1920) replaced fixed socket wrenches, each with its own permanent handle. Snap-on’s history says the founders made two hand-built sample sets of five handles and ten sockets and took over 500 C.O.D. orders with them, then built a direct-selling organization with 17 branches and 165 salesmen by 1925. Alloy Artifacts adds that the phrase “Interchangeable Sockets,” first used by the Edgar C. Guthard Company in 1919, became a catch-phrase for the replacement of the fixed socket wrench.

Manufacture shaped the tool. Allen Manufacturing applied its cold-forming process, patented in 1910 for set screws, to sockets by 1922, forcing the blank to flow around a mandrel; Alloy Artifacts says cold-forming is the dominant process for sockets today but was very novel in the 1920s. Drive sizes, which began with a single 1/2 inch size in 1920 at Snap-on, grew to 5/8 in 1923 and 3/8 in 1928, and the 12-point opening arrived in 1927. Johnson’s 1923 patent added a ratchet adapter to the Snap-on system, and Plomb and P&C added flex-head handles in 1926.

The modern socket and ratchet is specified by a standard. TEKTON’s product pages cite ASME B107.110-2019 for ratchet proof torque and the category of reversible ratchet handles, and Hand Tools Institute lists B107.110 as “Socket Wrenches, Handles, and Attachments” and B107.4 as the standard for driving and spindle ends. O*NET’s Tools Used table lists socket sets or ratchets in 10 of the 24 occupations mapped to this archive’s trades.

Timeline

1863
J. J. Richardson of Woodstock, Vermont, is granted US Patent 38,914 for a ratchet wrench with removable sockets (16 June).1
1864
D. M. Moore of Windsor, Vermont, is granted US Patent 45,334 for a ratchet wrench with a lever that disengages the detents (6 December); a forum post says a court decision of 1880 found that Moore had made a working ratchet in 1859.1 2
1869
The Lowell Wrench Company is founded in Lowell, Massachusetts, as the maker of a “triple-action” ratchet handle based on the Moore patent; an 1869 exhibition report explains that a nut can be turned by simple oscillation of the handle without removing the socket.1
1888
A notice for the Lowell Wrench Company’s bridge ratchet wrench appears; Alloy Artifacts says Lowell is believed to be the originator of large ratchet wrenches for construction work.1
1919
Blackhawk Manufacturing, managed by Joseph Johnson, offers a line of five interchangeable socket sets with machined and broached sockets in 1/2 inch square drive (May), according to Alloy Artifacts.1
1920
Joseph Johnson and William Seidemann found the Snap-On Wrench Company in Milwaukee; its first product is five handles and ten interchangeable sockets. Snap-on says two hand-built sample sets produced over 500 C.O.D. orders.1 2
1922
The earliest known notice of Allen Manufacturing’s Bay State socket sets appears (9 March); the sockets are made by cold-forming the steel blank around a mandrel, which Alloy Artifacts says was very novel in the 1920s.1
1923
Joseph Johnson is granted US Patent 1,443,413 for a socket wrench, a ratchet adapter for the Snap-on sets (filed 1 July 1920, issued 30 January 1923); Snap-on adds 5/8 inch drive sockets.1 2
1926
Plomb and P&C introduce flex-head (“hinge”) drive handles for sockets, according to Alloy Artifacts; Plomb’s 1926 catalog lists 13 and 18 inch 1/2 inch drive hinge handles.1
1927
Snap-on introduces double-hex (12-point) and double-square (8-point) broached sockets.1
1928
Snap-on adds 3/8 inch drive sockets.1

Where the sources disagree

Who made the first ratchet wrench?

J. J. Richardson, whose US Patent 38,914 was granted on 16 June 1863.1
US Patent 38,914
D. M. Moore had a working ratchet in 1859, before Richardson’s patent, according to a forum post citing an 1880 court case; Moore’s own patent 45,334 was granted on 6 December 1864.1 2
Garage Journal forum post (case not read); US Patent 45,334

Who introduced the interchangeable-socket wrench set?

Snap-on, in 1920, with five handles and ten sockets that “snapped on interchangeably.”1
Snap-on Incorporated
Blackhawk Manufacturing offered five interchangeable socket sets from May 1919, under the management of Joseph Johnson, who then founded Snap-on.1
Alloy Artifacts
A single ratchet handle with several interchangeable sockets was patented in 1863.1
US Patent 38,914

When did Snap-on file its first patent?

1923, a ratcheting attachment, the No. 6 Ratchet.1
Snap-on Incorporated
Filed 1 July 1920 and issued 30 January 1923 as US Patent 1,443,413, a ratchet adapter.1 2
US Patent 1,443,413; Alloy Artifacts

Gaps in the record (6)

The 1880 court decision that is said to have found a working Moore ratchet in 1859 has not been read; it is known only from a forum post.
Snap-on’s own history is the only source for the “over 500 C.O.D. orders” and the 17 branches and 165 salesmen figures except where Alloy Artifacts relies on trade notices; the notices themselves have not been read.
No source has been found for sockets before 1863 or for the earliest 12-point socket.
The ASME B107.110 and B107.4 texts have not been read; proof-torque values and drive-square dimensions are not given.
No sourced care instructions and no socket-specific safety instruction have been located, so care is empty and safety is the general OSHA statement.
No independent test data has been found, so buying is null.