Sheet Metal Fabrication At AjaxSheet metal fabrication is a mainstay of the metal forming industry, and a core competency at Ajax.
Innovations in machinery, workforce development, and materials purchasing enable Ajax to adapt the sheet metal fabrication process to produce virtually any part a customer may require. Ajax engineers apply Value Engineering principles to our customers’ work to keep costs as low as possible and speed workflow.
Generally, the sheet metal fabrication production process starts with materials selection. Types of common metals used in sheet metal fabrication include:
Aluminum is very lightweight yet still offers very good strength. It’s ideal for very low-temperature environments and also resists corrosion and rust, making aluminum a popular choice for marine, construction, and other industries that require long-lasting parts to be used in extreme environments.
There are dozens of types of steel available in today’s marketplace. Steel is chosen primarily for its durability and tensile strength, but also for the specific properties that each type of steel exhibits. For example:
Hot rolled steel is manufactured at a very high temperature and as a result can be formed more easily. It is typically cheaper than other types of steel since the manufacturing process is very streamlined. Hot rolled is ideal for applications where very precise shapes and tolerances are not required, such as railroad tracks or I-beams used in building construction.
Cold rolled steel is basically hot rolled steel that receives additional processing. This steel is cooled at a slow rate then rolled very flat. A “pickling” process removes any surface impurities or rust. Cold rolled is very workable and can be formed to very tight tolerances. Because the surface is clean, it can be finished through a variety of methods. Cold rolled steel is more expensive due to the additional production steps.
Stainless steel is an alloy (a mix of different metals) with good corrosion resistance and extreme toughness and tensile strength. Specialized machinery is required to cut and form stainless, and it gets expensive. Common applications include food processing equipment, medical instruments, nuts and bolts, appliances, and structural/architectural parts.
Galvanized steel has received a protective zinc coating to prevent rust, making it ideal for outdoor applications. The most common method of applying zinc are hot-dip galvanizing, in which the parts are submerged in a bath of molten hot zinc. Galvanized steel is less costly than stainless steel or aluminum and is used in street furniture, building frameworks, balconies, verandahs, staircases, ladders, walkways, and for making steel frames as a basic construction material for steel frame buildings.
Bronze is an alloy consisting primarily of copper with the addition of other ingredients such as tin. Bronze is much harder than copper and has a low melting point. Bronze resists water corrosion and is often used to make musical instruments, boat propellers, valves, and pipe fittings.
Copper is ductile, malleable, and electrically conductive, as well as corrosion-resistant. Applications include condenser/heat exchangers, radiator cores, hinges, ammunition shells, and electrical connectors. Alloying can increase or reduce the strength, hardness, electrical and thermal conductivity, corrosion resistance, or change the color.
Sheet Metal Fabrication Processes.
There are three main types of sheet metal fabrication:
- Metal forming
Each is outlined below.
Forming includes processes like bending metal blanks with a press brake or extruding with a turret press.
Fiber-optic laser cutting is by far the newest and most popular method of cutting sheet metal into a shape. Lasers use focused light beams to cut through or engrave material.
This video shows you how fiber lasers at Ajax cut through aluminum sheet metal.
Wire EDM technology uses a strand of wire as a cutting tool to achieve extreme accuracy when producing incredibly delicate, accurate parts. Since only one tool is required it is also a low cost alternative. Wire EDM (electrical discharge machining) is suited for projects that have intricate tolerances, material stress limitations, and/or surface finish requirements.
Wire EDM can also be a high volume alternative for material types that are too brittle to be production stamped by a die. By stacking flat layers, machines are capable of wire EDM cutting high volumes of precision parts.
Joining encompasses the processes of welding, brazing, riveting, and adhesive use.
Welding comes in several forms, including MIG, TIG, and stick. It acts by fusing the metal sheets together through melting them, while adding a filler.
Brazing is a similar process, but it acts by melting a filler without melting the sheets.
Riveting relies on small metal parts to join sheets of material by embedding them through both sheets.
Adhesives hold together metal sheets either alone, as in the case of structural adhesives, or in conjunction with another joining method, as with machinery adhesives.
Sheet Metal Fabrication Machinery
Sheet metal fabrication at Ajax begins with programming (modeling) our customer’s part in CAD/CAM software like SolidWorks and Radan to pass along instructions to the computerized fabrication machinery on the plant floor. Fabrication machinery operators use this information to maximize the number of parts created from the material, minimize material waste, and ensure that the finished part conforms to the Ajax customer’s specifications.
The most common types of sheet metal fabrication machinery are press brakes, punch presses, turret presses, stamping presses, and servo presses.
Press brakes use hydraulic pressure and tool and die setups made of super-hard tool steel to bend, or form, various types of metal into specific shapes as instructed by the machine’s computer.
Punch presses use piercing tools to create holes, extrusions, and outlined shapes in sheet metal.
Turret presses operate like punch presses, only they are capable of creating far more elaborate extrusions and shapes, and can operate at a very high speed. Turret presses can also automatically change punch tools on the fly to speed production.
Stamping presses operate like a mechanized hammer and anvil. Stamping presses use precision-made male and female tool and die setups and extreme pressure to shape, or “stamp” a metal part into the desired form.
Servo presses are very advanced stamping presses that use an electric servomotor to drive a tool down on material with a high level of force and control. Servo presses can accurately control cycle rate and pressure loads, enabling these presses to form thick, strong material like stainless steel without tearing the material.
Once the metal has been fabricated there are finishing processes that can be performed to enhance its properties, including sandblasting, deburring, annealing, and coating.
Ajax provides part prototyping services, short-run, low volume production, and high-volume, long-run metal part production. Your Ajax sales engineer can assist you in selecting the best materials and production process for your metal part. Contact Ajax today.