Many manufacturing jobs involve cutting mild steel into custom shapes. Some of the most effective steel plate cutting methods include oxy fuel flame cutting, plasma cutting, and laser cutting, but there is no one-size-fits-all approach. The best way to cut a steel plate depends on the plate’s thickness and project requirements such as tolerance and edge quality. At Accurate Metal Products, we carefully consider each client’s budget and requirements to select the most effective plate cutting approach.
Understanding the Different Cutting Methods
Although oxy fuel flame cutting, plasma cutting, and laser cutting all use heat to slice through metal plates, they are each different with distinct advantages and disadvantages.
Oxy fuel flame cutting is a thermal cutting technique in which a gaseous fuel rapidly oxidizes the steel along a set path. The process is highly efficient for steel plates up to 12 inches in thickness.
First, a stream of oxygen and fuel heats the metal to its ignition point, which, for mild steel, is approximately 700-900° C. Next, a stream of pure oxygen runs across the metal, weakening the metal and generating iron oxide. The oxidation reaction continues, with the stream of gas blowing off the iron oxide, until the plate is cleanly sliced.
Oxy fuel flame cutting is a versatile and precise process, used to achieve tolerances of ±.063 to .250 inches across a range of industry applications. Some sectors that benefit the most from oxy fuel flame cutting include:
Like oxy fuel flame cutting, plasma cutting leverages a stream of hot gas to cut metal along a predetermined path. The difference lies in how plasma cutting machines direct the gas.
A plasma torch uses a copper nozzle to focus a stream of superheated, ionized gas. Within the nozzle is an electrode, which generates an arc of electricity between the nozzle and the steel plate. The combination of compressed gas and electricity yields a high-powered, highly precise stream of gas that cuts through metal with ease. While manual plasma cutting is possible, we typically use advanced CNC plasma cutters for maximum speed, precision, and cutting area. With these machines, we achieve cutting speeds exceeding 10m per minute without sacrificing accuracy.
As a fast and precise manufacturing technique, plasma cutting is popular across many industries, including:
- Industrial construction
Whereas plasma cutting and oxy fuel flame cutting both use a stream of gas to cut the metal, laser cutters instead leverage an intense laser beam to heat and slice along a precise path.
Different laser cutters are suitable for different types of plate cutting projects. CO2 lasers, which use carbon dioxide as a medium, are weaker and better suited to soft materials or engraving. Fiber lasers are more powerful, incorporating optical fibers as their medium, and can cut a wider range of materials. They also tend to be more precise and efficient. On the whole, though, either laser cutting technique can be highly effective when used in the right setting. Laser cutting is especially valuable for precise, intricate designs with tight tolerance requirements.
Some industries that often benefit from laser cutting include:
- Automation / Production Equipment
- Material Handling
- Municipal/ Government
- Power Generation
Choosing the Best Method to Cut Steel Plate
While there is no single best steel plate cutting method, it can be challenging to identify which of these techniques is best suited for a given product. Most projects could theoretically be completed with any of these machines, but to optimize efficiency and precision, it’s best to consider the following constraints before making a decision:
- Steel Thickness: Oxy fuel flame cutting can cut the broadest range of plate thicknesses, and it is the only method discussed that should be used for steel thicker than 2”. Oxy fuel flame cutters can manage plates up to 12” in thickness, so if your component calls for a very thick construction, the decision may be made for you. By contrast, laser cutting is the best choice for ultra-thin plates, including plates thinner than 0.1” thick. Medium-thickness jobs can be completed with either laser cutting or plasma cutting, depending on other variables.
- Precision: Plasma cutting, oxy fuel flame cutting, and laser cutting all achieve quality edges with precise tolerances. However, plasma cutting results in the best finish for angled surfaces, and specific tolerances for all processes depends on the material and control method. For instance, CNC cutting will always result in better tolerances than manual cutting.
- Edge Quality: Compared to oxy fuel flame cutting, plasma cutting and laser cutting may result in cleaner edges without secondary processing.
- Metal Properties: Plasma cutting is better for conductive or corrosion-resistant metals than oxy fuel flame cutting, and laser cutting may be challenging with highly reflective materials.
- Other Considerations: Cost, speed, and secondary services can impact the selection between these three methods. For instance, laser cutting tends to be slower, and oxy fuel cutting tends to be cheaper. Consult with your engineering team for specifics on budget, lead times, and secondary operations.
Contact Us for More Information on Metal Cutting Methods
Oxy fuel flame cutting, laser cutting, and plasma cutting are all excellent, effective steel plate cutting processes, but not all techniques are appropriate for every project. Considerations like thickness, edge finish, and cost can influence your selection, so it pays to consult with an experienced metalworking professional before beginning an order.
Accurate Metal Products has offered premium metalworking services for over 25 years. Our offerings have grown to include plasma cutting, laser cutting, and oxy fuel flame cutting services, as well as grinding, blasting, and heat treating. We offer a full range of value-added services, including cleaning, packaging, barcoding, and free delivery within 150 miles of our Milwaukee or Rockford facilities.