Raising (metalworking)

This is a copper vase formed using the process of raising.
Anticlastic forged sterling bracelet.

Raising is a metalworking technique whereby sheet metal is formed over a stake or other solid object by repeated 'courses' of hammering and annealing. The sheet metal, held at an angle to the stake, is formed using mechanical advantage by hammering just in front of the contact point. When executed correctly raising allows the smith to efficiently shape the metal without thinning thus avoiding the risk of cracking, a common occurrence with parallel forming processes such as sinking or stretching. In raising the metal at the edge of the sheet is compressed and thickened as the form is necked in. This technique is an essential part of silversmithing and is used to create seamless vessels such as vases, cups, bowls, carafes, pitchers, euers, etc.

In traditional raising, sometimes referred to as Synclastic raising, the dominant curves of the object being forged are at right angles and move in the same direction; as in a bowl. This results in a surface possessing elliptic geometry.

Anticlastic raising, on the other hand, refers to shaping an object where the dominant axes move in opposite directions; a familiar example of this is a potato chip. This results in a surface possessing hyperbolic geometry.


This article is issued from Wikipedia - version of the 3/30/2013. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.