Sledgehammer

How it works

The user holds the far end of the handle in both hands and swings the head in an arc, so that the weight of the head and the speed of the swing do the work. Moxon, writing for blacksmiths in the later seventeenth century, describes the largest sledge as swung above the head and let fall at arm’s end with as heavy a blow as the workman can give.

The blow lands on the work or on another tool. In Googerty’s forge, punches, chisels and the flatter are struck with the sledge. Googerty’s school forging text of 1915 calls for a ten-pound sledge with a 26 inch handle for every two forges. Knight’s dictionary describes the about-sledge as the largest hammer of the blacksmith, used by his helper in turn with the smith’s own smaller hammer.

The head is hard and the handle must stay tight in it. Council Tool says its 10 lb double-face sledge head is forged tool steel, machined with a radius and chamfer on the face and heat treated to a hardness of Rc 45 to 60 after machining. Its 36 inch hickory handle is dried before turning and driven hydraulically into the head, where a serrated aluminum wedge holds it.

Anatomy

Head: Forged steel, usually with two faces. Council Tool lists its sledges as double-face.
Faces: Machined with a radius and a chamfer. CCOHS says beveled faces are less likely to chip or spall.
Eye: The hole through the head that receives the handle.
Handle: Hickory, 36 inches on Council Tool’s sledges and 26 inches on the school-forge sledge in Googerty. Some are fiberglass.
Wedge: On Council Tool’s sledges, a serrated aluminum wedge that secures the handle in the head.

Variants

About-sledge: The largest blacksmith’s hammer in Moxon and in Knight’s dictionary; swung over the head by the helper.
Up-hand sledge: In Moxon, a smaller sledge used with both hands held in front, seldom lifted higher than the head.
Flogging hammer: In Knight’s dictionary, a machinist’s hammer intermediate in size between the sledge and the hand hammer.
Double-face sledge: Two striking faces; Council Tool lists 10 and 16 lb models.
Drilling hammer: A shorter, lighter head of 2 to 4 lb, for which Estwing names striking chisels, punches, star drills and hardened nails.

Specifications

Head weight · lb: Council Tool offers 10 and 16 lb double-face sledges; Googerty specifies 10 lb for the school forge.
Handle length · in: 36 in. on Council Tool’s sledges; 26 in. on Googerty’s forge sledge.
Face hardness · Rockwell C: Council Tool states a range of Rc 45 to 60 for its 10 lb sledge.

Made to

ASME B107.400
OSHA 29-CFR-1926-301

Safety and care

Safety

Look behind and above before swinging and keep clear of other workers (CCOHS).
Use a handle that is tight in the head and free of cracks and splinters (OSHA 29 CFR 1926.301(d)).
Do not strike with the side or cheek of the head, and do not strike a hammer against another hammer or a hardened object (CCOHS).
Wear safety goggles; Estwing says bystanders should also wear them.

Care

Discard a sledge whose face is chipped or mushroomed, or whose handle is dented, cracked or splintered (CCOHS; Estwing).
Do not redress, grind, weld or reheat-treat the head (CCOHS).
Council Tool finishes its heads with clear lacquer to deter rust.

Tips

Stand in front of the anvil and make the first blow a light one
Googerty’s school forging text says that when using the sledge hammer the worker should stand in front of the anvil and not at its side, and let the first blow be a light one.1
Do not wedge the handle of a tool that will be struck with a sledge
Googerty says a punch or anvil tool handle should pass through the eye about an inch and never be wedged, because a wedged handle is more likely to break under a glancing sledge blow. If the tool begins to work off the handle, the protruding end lets the movement be seen.1
Match the head weight to the work
Moxon distinguishes the up-hand sledge, swung with both hands in front and seldom lifted above the head, from the about sledge, swung overhead for the largest work. Council Tool offers double-face sledges of 10 and 16 lb.1 2 3
Use a lighter drilling hammer to strike chisels and punches
Estwing names the drilling hammer, in 2, 3 and 4 lb heads, as the tool for striking chisels, punches, star drills and hardened nails, and advises a striking face about 3/8 in. larger than the struck face.1 2
Read the hardness range on the label
Council Tool states a heat-treated hardness of Rc 45 to 60 for its sledge, with the heat treatment done after machining for greater depth of hardness. The range sets how the head wears and how likely it is to chip against hard objects.1

History

Earliest documented

Old English period

England

The Bosworth-Toller Anglo-Saxon Dictionary defines the Old English slecg as a sledge-hammer or mallet (Latin malleus) and cites it from glossaries, a monastic colloquy and a homily. Its dates are not stated in the entry. The related slecgwyrhta means one who works with a hammer, a worker in metals. Older evidence for heavy striking tools is archaeological: Petrie describes hand-held stone mauls used for dressing hard stone in the pyramid period, one from Meydum of the Third Dynasty.1 2

The sledgehammer is a tool of weight. The earliest heavy striking tools in the Egyptian collection that Petrie describes are mauls of hard stone, used in the pyramid period to bruise down the faces of hard stone before polishing; his text does not say how they were held. Handled forms of the large hammer are recorded later; Petrie finds the larger smith’s hammer only in Roman times, and says the early iron hammer of the Greeks was small and light.

The word is older than most records of the tool. The Bosworth-Toller dictionary gives slecg as the Old English for both sledge-hammer and mallet, from sources it cites by their editions but does not date in the entry. One word thus named both a sledge-hammer and a mallet. By the seventeenth century Moxon treats the sledge as a blacksmith’s hammer in two sizes, and the mallet appears elsewhere in his work as a joiner’s and carpenter’s tool.

The forge fixed the working method. Moxon’s about-sledge is swung by an under-workman, who lets it fall from above the head. Knight’s dictionary describes the same arrangement, with the helper wielding the about-sledge turn and turn about with the smith’s own hammer, and defines the fore-hammer as a sledge working alternately or in time with the hand-hammer. Googerty’s 1915 text carries these practices into the school forge, with a ten-pound sledge shared between two forges.

The modern sledge is defined by materials and heat treatment. Council Tool’s 10 lb sledge is a forged tool steel head, machined and then hardened to Rc 45 to 60 so that the hardness reaches deeper, on a 36 inch hickory handle held by a serrated aluminum wedge. The company says its sledges meet ASME B107.400-2018. The 2008 edition of that standard incorporated seven earlier ones, among them the standard for heavy striking tools.

The sledgehammer is a general-purpose heavy tool. O*NET’s Tools Used table links the sledge hammer commodity class to 38 occupations. Its hazard is the one the other striking tools share: a hard head that can chip against another hard object, which CCOHS and Estwing both warn against.

Timeline

Third Dynasty
Hand-held stone mauls for dressing down hard stone surfaces are in use, according to Petrie, who illustrates an example from Meydum.1
Old English period
The word slecg is recorded for a sledge-hammer or mallet in glossaries and in a homily; the entry gives no dates.1
Roman period
The larger size of smith’s hammer appears in Roman times, according to Petrie; the Greek iron hammer before it was small and light.1
1677 onward
Moxon describes three hammers of the blacksmith’s trade: the hand-hammer, the up-hand sledge and the about sledge, the last the biggest of all.1
1870s
Knight’s American Mechanical Dictionary defines the about-sledge, the flogging hammer and the fore-hammer, a sledge-hammer working in time with the hand-hammer.1
1886
John Pickett Council founds the business that becomes Council Tool Company, a maker of heavy-duty hand tools, according to the company.1
1915
Googerty’s school forging text specifies a ten-pound sledge hammer with a 26 inch handle for every two forges and gives rules for its use.1
2008
ASME B107.400-2008 incorporates the earlier standard for heavy striking tools, ASME B107.54, along with the standards for nail hammers, ball-peen hammers and others.1
2018
Council Tool states that its sledges meet or exceed ASME B107.400-2018, reaffirmed in 2023.1

Gaps in the record (6)

The dates of the Old English sources cited in the Bosworth-Toller entry are not stated there; the original editions were not read.
No museum record of a dated sledge head has been located, and Petrie’s text does not say how his mauls were held, and they are not shown to be sledges.
No nineteenth-century trade catalog listing of sledges has been located; the Sargent & Co. 1869 text read for other hammers gives no readable sledge entry.
The Knight’s dictionary copy read is a 1876 printing; the first edition is reported to be 1874 and was not read.
Council Tool’s hardness range and standards conformance are the company’s statements; no independent test or failure data has been located, so buying is null.
ASME B107.400 text was not read; only the table of contents of the 2008 edition. The standard slugs are unverified.