What is Carbon Steel Sheet Metal Fabrication?
Carbon steel sheet metal fabrication involves the production of parts using sheets of carbon steel, taking advantage of a multitude of techniques including stamping, pressing, drilling, cutting, and polishing. The high strength of carbon steel makes it an ideal material for engineers, allowing it to be used in a wide range of applications such as structural components, enclosures, brackets, fittings, and faceplates.
Furthermore, the ability of carbon steel to be heat-treated and welded also makes it suitable for use in a diverse range of manufacturing techniques, including welding and braising. Additionally, the low cost of carbon steel makes it a cost-effective option for adding structural integrity to projects without exceeding budgets, making it an ideal choice for numerous industries.
Types of Carbon Steel Sheet Metal
Carbon steel comes in numerous types, all with various characteristics such as heat treatment and impurities (all of which change the properties of carbon steel).
For example, A1008 Cold Roll Carbon Steel is ideal for those manufacturing parts that will undergo additional fabrication steps including welding and machining. The smooth finish of A1008 makes it ideal for parts that will be visibly exposed to customers, including furniture and decorative pieces.
On the opposite end of the spectrum, A1011 Hot Rolled Carbon Steel is a much stronger variant of carbon steel, making it ideal for structural parts that support weight. However, the thin rust scale that forms on A1011 makes it unsuitable for use outside of enclosed designs, meaning that it is rarely seen by the public.
Some applications, however, require protection from the environment for the lifetime of the product, and this is where A653 Galvanneal Steel can be beneficial. The use of a zinc-iron alloy galvanisation provides extreme corrosion and oxidation resistance, making it ideal for environments that experience wide temperature swings and moisture. Such parts include automotive components, computer cases, and door handles.
Finally, A588 Weathering Steel is an extremely unusual variant due to its ability to rust. Once rusted, the red patina formed on the surface provides a layer of corrosion protection, and this makes A588 ideal for applications in extreme environments. While A588 is capable of being used structurally, its unique rusting properties also make it ideal for decorative pieces.
Options for Surface Finishes
The wide range of available surface finishes for sheet metals provides engineers with a multitude of options for their designs, whether to improve the aesthetic appearance or provide protection against corrosive environments. However, as carbon steel is prone to rusting, any surface finish may require additional layers to prevent corrosion, including coatings and paint.
Removing debris and sharp edges is a critical step in the sheet metal production process, with deburring being particularly useful in areas where precision is essential. Sanding can also be used to remove oxidation and dirt that may interfere with welding and soldering processes, something which is commonly found in mechanical assemblies.
The smooth finish provided by polishing can also benefit mechanical assemblies by improving the smoothness of moving parts, such as gears and cogs, but such a finish must be protected against oxidation to maintain its appearance and longevity. Printing is another option for those needing graphics with colour variations, and can be particularly useful for identifying different types of materials and equipment.
Finally, engraving can be used to integrate key information such as part numbers and serial codes, making it ideal for use on faceplates and other areas that need tracking and identification which doesn’t fade over time.
Design Tips for Your Carbon Steel Sheet Metal Project
When tackling projects that require precision and accuracy, carbon steel is an excellent material to choose due to its high strength, malleability, and machinability. However, laser-cut carbon steel parts should be used in applications where edge hardness is not critical as laser cutting changes the temper of the edge.
It is also important to take note of laser kerf when laser cutting carbon steel. Simply put, the beam width increases as it moves away from the laser head, and this results in a wider cut on the underside compared to the top side. As such, design creations should take into account that the top edge of a part will be the narrowest.
Another aspect to consider when working with carbon steel is the sparking that occurs when the metal is cut. This can lead to challenges in applications where ignition is a possibility, and therefore engineers should take measures to prevent such ignition (through the use of moisture or other inert gasses).
Those designing mechanical parts requiring a high degree of precision should consider photochemical etching, and those looking to reduce the weight of their parts should consider aluminum.
Finally, engineers should also take advantage of cut-outs to reduce the weight of a part, but this will undoubtedly reduce the structural capabilities of the part. As such, cut-outs should only be used in areas that are not essential to the function of the part.
Tips for using carbon steel in your next project
Is carbon steel expensive?
Carbon steel is anything but expensive, being one of the cheapest metal options available to engineers. The simplicity of carbon steel, its lack of alloying, and large-scale use makes it an ideal material for mass production.
As such, the cost of carbon steel is significantly lower than that of other engineered materials such as aluminium and copper. The ability of carbon steel to be easily welded also makes it highly adaptable in manufacturing stages, and its high strength-to-weight ratio makes it excellent for structural applications. However, the high rust susceptibility of carbon steel means that additional protective measures will be needed to ensure a long and healthy service life.
What can carbon steel be used for?
Carbon steel is an excellent material for use in structural parts such as frames, enclosures, and cases due to its high tensile strength. Its high strength also makes it ideal for fittings, brackets, and other internal mechanical parts. But carbon steel is not suitable for decorative pieces or aesthetic purposes as it rusts easily, losing its smooth finish and clean appearance.
What types of carbon steel resist corrosion?
While numerous coatings and galvanising can be used to resist the effects of corrosion and rusting, only a handful of carbon steel options actually resist corrosion.
The most common of these is A53 grade steel which is coated with galvanised to resist rusting, and while this increases the part cost, it provides an excellent low-cost option for those needing a basic steel part.
Other options include A36 which is generally used for structural purposes, and is not recommended for use with corrosive environments, and SS 304 which is a stainless steel that resists corrosion and rusting, but is more expensive as a result.
What machining methods is carbon steel compatible with?
When it comes to machining, carbon steel is highly adaptable and can easily be machined using a wide range of different techniques. Firstly, drilling is by far the easiest method for creating holes, as this can be done using standard drill bits in a handheld drill or a drill press.
Carbon steel can also be laser cut, CNC machined, bent, pressed, cut using a water jet, and cut using a plasma cutter. While CNC machining offers great precision, laser cutting is by far the most economical method due to the lack of tooling bits needed. However, if thick parts are required (greater than 6mm) Plasma and water jet cutters reign superior.
