The most common way to cut metal by far is with a Sawzall, a bimetal blade, and enthusiasm. This is, however, far from the best way to cut metal. The resulting cuts are typically anything but straight, and if the metal is thicker than a nail or sheet metal, cutting through it with a Sawzall will take a substantial amount of time.
When it comes to cutting sheet metal for use in construction, welding, or machining, angle grinders are a better choice. Equipped with an abrasive cutting disc rather than a grind or polish disc, angle grinders can make straight clean cuts.
However, cutting through anything thicker than a typical angle iron is likely time-consuming and exhausting. The best way to cut sheet metal depends on the type of metal, dimensions, and end-use case.
Types of Metal Cutting Processes
The processes of cutting metal can be broadly divided into two categories. The first is the mechanical process of direct contact between the metal and a metal cutting blade or an abrasive surface. These include a variety of saws and even processes like water jet cutting. These processes are common in small and large shops, and many of them are the best way to cut metal for professional work. While friction and the resulting heat input can be an issue, heavy machining oils can prevent damage to the metal.
The second category is nonphysical cutting processes. These are less common than strictly mechanical processes; many are new or nascent technologies. In these processes, thermal or electrical energy is directed into the metal, melting through it and leaving two separate pieces behind. It can also include things like laser cutting. Although, in principle, it could be used for the precision cutting of large industrial metal pieces, laser cutting’s most common application is precisely cutting ornamental work like lettering for custom signs.
In either type of cutting process, the best way to cut metal is going to vary on a case-by-case basis. For example, overheating the metal, changing its properties, and rendering it unfit for purpose is possible whether one is working with mechanical or electro-thermal cutting processes. Whatever cutting process is chosen, the best way to cut metal depends on the parameters for the metal, the process, and the desired result.
Mechanical Metal Cutting Processes
Cutting metal mechanically is something that everyone has done. If you have used a can opener, you have successfully cut metal mechanically. Doing so in a professional setting requires more in the way of equipment. This can be as simple as using common wood-cutting tools equipped with carbide metal cutting blades.
Types of Metal Cutting Tool
The following are the types of metal cutting tools one can use today:
Any of these metal cutting tools provides a practical way to cut softer metals, like aluminum, and can be considered the best way to cut metal, depending on the metal and use case. However, this methodology may not provide the necessary speed for a small shop that must cut lots of aluminum. These saws are also not viable for cutting harder metals in significant amounts.
While adding an abrasive blade to a circular saw and cut steel is technically feasible—and many have tried to do this—the results are likely frightening and hazardous to the operator. Cutting steel and harder metals requires upgrading metal-cutting processes to the next level.
Electrical and Thermal Methods of Cutting Metal
Heat is humanity’s oldest means of working with metal, and it is still one of the preferred methods of cutting metal. Oxy-acetylene cutting torches are a common metal cutting tool in shops and construction sites the world over. They are handy for cutting pieces of rebar and steel plates in an environment where options are limited. However, they aren’t typically used for precision cuts, and typically there is a fair amount of grinding metal after cutting in order to clean up the cuts so the metal can be used.
There are also a variety of improvements that have been made to this basic flammable gas metal cutting setup. These include replacing acetylene with a different, hotter burning gas and mechanical controls for more precise and cleaner cuts.
However, this still may not be acceptable for some uses as it generates large heat-affected zones. It also does not work very well with metal like aluminum, which tends to bond with oxygen in the atmosphere when heated. This has led to the development of plasma cutting and laser metal cutting tools.
These very high-heat metal cutting processes lead to less heat being input into the metal because they cut through the metal so quickly. Due to either a shielding gas in the case of plasma cutters or the ability to cut through the metal very quickly, these cutting methods are very capable of cutting through materials like aluminum without the issues that occur with gas-cutting processes.
Finding the Best Way to Cut Metal
When it comes to determining the best way to cut metal, it depends on the workflow and the needs of the final product. Top-tier laser and plasma cutters won’t be of much use if they are paired with an inexperienced operator who cuts with the distinctive wobble that comes from being inexperienced. Pairing plasma and laser cutting with CNC metal cutting tools will address this issue, but it is probably overkill for most metalworking shops. While small-scale CNC cutters are fairly affordable, industrial versions capable of dealing with inches-thick metal and higher are costly.
The same holds true for many mechanical cutting methods. While these upfront costs are lower than things like plasma or laser cutters, specialized carbide blades, and high-powered saws aren’t cheap. This is especially true for those with the power and specialized setups needed for thicker materials or high-volume production. Training employees to use this equipment and developing suitable parameters is likely to be quite expensive both in terms of equipment damage and miscut metals. It might not be obvious that machining oils are required, and an inexperienced employee is unlikely to know the right cutting oil for machining aluminum vs. what is right for hardened steel. They also aren’t well adapted to specialized shapes like circles.
The lesson to be learned is that the best way to cut metal for most, whether they are hobbyists or metal production shops, is to use expert industrial metal-cutting services. These can deliver process-ready metals ready for final assembly or machining to your door. Whether it is cut to order aluminum or titanium or other hard metals like superalloys, professional metal cutting saves both time and money.