A holdfast or hold fast is a form of temporary
clamp used to hold a workpiece firmly to the top or side of a
wooden workbench or the top of an
anvil
An anvil is a metalworking tool consisting of a large block of metal (usually forged or cast steel), with a flattened top surface, upon which another object is struck (or "worked").
Anvils are as massive as practical, because the higher th ...
.
A form of
bench dog
A bench dog is a removable clamp used on a woodworking workbench to hold an item fast while being worked. It is characteristically used in concert with an adjustable dog on a bench vise, allowing an item compressed between the two to be held fa ...
, a traditional holdfast has either a curved or flat top. Its shank is slid loosely into a “dog” hole in the bench or anvil until the tip of its hook touches the work. It is set by hitting its top with a
mallet
A mallet is a tool used for imparting force on another object, often made of rubber or sometimes wood, that is smaller than a maul or beetle, and usually has a relatively large head. The term is descriptive of the overall size and proport ...
or
hammer
A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nails into wood, to shape metal (as w ...
, which causes the shaft to wedge tightly against the sides of the hole. A tap of its back side near the top releases it.
Contemporary holdfasts are commonly designed to fit in holes, somewhat narrower than had been traditional. Scrap pieces of wood or leather are often used between the holdfast and the workpiece to prevent marring it.
An adaptation of the holdfast is threaded, sometimes known as a “screwdown”, which is tightened rather than tapped in place.
History
Based on a fresco discovered in the ruins of
Herculaneum
Herculaneum (; Neapolitan and it, Ercolano) was an ancient town, located in the modern-day ''comune'' of Ercolano, Campania, Italy. Herculaneum was buried under volcanic ash and pumice in the eruption of Mount Vesuvius in AD 79.
Like the nea ...
, holdfasts are known to have been in use since at least the 1st century AD. They are also described and illustrated in early European books on woodworking, such as
Joseph Moxon's 1678 edition of ''Mechanick Exercises'' and
André Jacob Roubo's 1774 ''L'Art du Menuisier.'' The term has been in use since at least the 16th Century. Use declined throughout the 20th century, but has seen a resurgence in recent years.
Gallery
File:Holdfast illustration adapted from L'Art du Menuisier.png, Illustration from L'Art du Menuisier (1769) demonstrating how the holdfast is secured in the workbench hole
File:Engraving showing two putti using a Roman workbench, based on a fresco from the ruins of Herculaneum.jpg, Roman workbench with a holdfast, based on a 1st Century AD fresco from the ruins of Herculaneum
File:Cc&j-fig40--bench holdfast.png, Illustration of a screwed holdfast from ''Cassell's Carpentry and Joinery'' (1907)
File:Men veneering from L'Art Du Menuisier-Carrossier (Roubo).png, Illustration from L'Art du Menuisier (1769) showing a workbench with holdfasts in use
See also
*
Bench dog
A bench dog is a removable clamp used on a woodworking workbench to hold an item fast while being worked. It is characteristically used in concert with an adjustable dog on a bench vise, allowing an item compressed between the two to be held fa ...
*
Clamp (tool)
A clamp is a fastening device used to hold or secure objects tightly together to prevent movement or separation through the application of inward pressure. In the United Kingdom the term cramp is often used instead when the tool is for temporar ...
References
Woodworking clamps
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