The importance of design in custom sheet metal fabrication
The first step in custom sheet metal fabrication is design. In most cases, design is collaboration between the client and the fabricators in conceptualizing the exact product part including its characteristics. CAD or computer-aided design allows the technician to convert a solid metal model into a sheet metal model that will include specific material grades, thickness, bend radii and reliefs for welding not to mention the most important which is the bill of materials. Fabricating a non-standard metal part from sheet metal requires considerable planning because insufficient preparation can result into structural weaknesses. Through CAD program, any potential structural weaknesses will be identified prior to the fabrication process.
How to cut sheet metal through basic cutting tools
The process of cutting a pattern in sheet metal for custom fabrication can be achieved through a variety of methods and cutting tools. In order to determine the most appropriate method, it is important to take into consideration several factors like flexibility, speed, accuracy, finish, cost and automation. Using a chisel and hammer is the most basic type of cutting sheet metal however the accuracy of the cut will depend on how patient the fabricator is in lining up the chisel accurately. Since this method of cutting is limited it is not often used by fabricators because it affects productivity. Hacksaws which are also called jeweler’s saws is another type of basic hand tool used to cut sheet metal but it has limitations in turning radius and depth because of its geometry. Electric shears and double cutters are common sights in fabrication shops. These portable tools are basically handheld and chew away at the metal as the cutting blade is maneuvered on its intended path.
How heat cutters are used in cutting sheet metal for custom fabrication
Gas torches work well with sheet metal because their burn temperature is relatively lower than melting temperature. The heat from the torch is combined with steady stream of oxygen that oxidizes sheet metal and blows the weakened metal away. Gas torches have the capability to cut through thick sheet metal at a relatively high speed.
The method of using a plasma torch is similar to the oxyacetylene torch however, instead of oxidizing sheet metal; it ionizes with a strong electro-magnetic field. Aside from the heat of the torch that weakens sheet metal, it allows the weakened metal to be blown away through high pressure air. The plasma torch is usually the cutting tool of choice by fabricators of custom sheet metal because it can easily be maneuvered in tight places to achieve close tolerances.