Sheet Metal Fabrication refers to the bending and shaping processes of sheet metal techniques. Sheet metals can be given all sorts of complex hollow shapes and sections, and the equipment used for these processes, range from simple hand tools, to sophisticated power-operated automatic machinery. Sheet metal work usually starts with a preliminary operation such as cutting, perforating or slitting etc. with tools that exercise some type of shearing action. These may be simple hand scissor like cutting tools, or power operated bench shears for heavier gauge materials. There are several kinds of power-driven shearing machines, and such machines comprises of a fixed blade and a moveable blade. The process of ‘punching’ refers to operations carried out with the use of a punching machine (or press) and this means to pierce a hole in the metal article, with the appropriate tool fitted in the machine, and clipping (the removal of surplus metal).
Another type of sheet metal fabrication is shaping. A wide range of shaping operations known as folding or bending, are done on presses and similar machines, as well as operations such as
* Grooving
* Seaming Stamping
* Crimping & Beading
These processes are used for the stiffening and shaping of sheet metals, the forming of tubular sections for circular shapes, and other numerous purposes.
Angles and sections can be formed by bending or folding. Coiling is the process of coiling over the edge of a sheet metal component, to increase the strength and provide a suitable edge, and is applied by a rolling or coiling tool on a press. Circular or cylindrical shapes such as tubes are performed and produced on a roll-forming machine. Press forming operations can include
* Cupping
* Embossing
Cupping refers to the conversion of a blank into cup form. Embossing refers to a particular design applied for strengthening purposes, and can be produced on a partly finished component. Cupping is usually the first stage in an operation known as forming, in which the appropriate tool is used to give the article its final shape. Seaming is generally used for joining sheet metal parts and is for example, often used for joints in metal roofing. Flanging is the process of forming a flange on a sheet metal component. Beading is the process of making depressions for the purpose of embellishment or stiffening, etc, and it may be done by the use of suitable or specifically shaped rollers. There are many other techniques used in sheet metal fabrication and some of these can include:
* Deep Drawing
* Marforming
* Flow Forming
* Spinning
With the advancement of today’s technology, many of these techniques are now applied with the use of computer controlled machinery.
By John Cheesman