Sinking
Encyclopedia
Metalworking
Metalworking is the process of working with metals to create individual parts, assemblies, or large scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts and delicate jewelry. It therefore includes a correspondingly wide range of skills,...
technique whereby flat sheet metal
Sheet metal
Sheet metal is simply metal formed into thin and flat pieces. It is one of the fundamental forms used in metalworking, and can be cut and bent into a variety of different shapes. Countless everyday objects are constructed of the material...
is formed into a non-flat object by hammer
Hammer
A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...
ing it into a concave indentation. While sinking is a relatively fast method, it results in stretching and therefore thinning the metal, risking failure of the metal if it is 'sunk' too far.
Sinking is used in the manufacture of many items, from jewellery
Jewellery
Jewellery or jewelry is a form of personal adornment, such as brooches, rings, necklaces, earrings, and bracelets.With some exceptions, such as medical alert bracelets or military dog tags, jewellery normally differs from other items of personal adornment in that it has no other purpose than to...
to plate armour
Plate armour
Plate armour is a historical type of personal armour made from iron or steel plates.While there are early predecessors such the Roman-era lorica segmentata, full plate armour developed in Europe during the Late Middle Ages, especially in the context of the Hundred Years' War, from the coat of...
.
Technique
Mallet
A mallet is a kind of hammer, usually of rubber,or sometimes wood smaller than a maul or beetle and usually with a relatively large head.-Tools:Tool mallets come in different types, the most common of which are:...
-driven punch to force sheet metal into an indentation. The exact nature of these tools will vary greatly depending on the scale and nature of the work. Fine work will typically require a small doming punch and a doming block. Larger work may involve a special sinking hammer and sinking stump
Tree stump
After a tree has been cut and felled, the stump or tree stump is usually a small remaining portion of the trunk with the roots still in the ground. Stumps may show the age-defining rings of a tree. The study of these rings is known as dendrochronology....
. The forming indentation need not be permanent; metal can be sunk into sandbags or lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
blocks.
Sinking may be done when the metal is cold or hot. If a piece is extensively worked cold, it will work harden
Work hardening
Work hardening, also known as strain hardening or cold working, is the strengthening of a metal by plastic deformation. This strengthening occurs because of dislocation movements within the crystal structure of the material. Any material with a reasonably high melting point such as metals and...
and require annealing
Annealing (metallurgy)
Annealing, in metallurgy and materials science, is a heat treatment wherein a material is altered, causing changes in its properties such as strength and hardness. It is a process that produces conditions by heating to above the recrystallization temperature, maintaining a suitable temperature, and...
to prevent cracking.
It also may be useful to planish
Planishing
Planishing is a metalworking technique that involves finishing the surface by finely shaping and smoothing sheet metal...
the metal to smooth it out.