What Is Stainless Steel Cutting?
Stainless-steel cutting involves using various techniques such as plasma cutting to get rid of excess material from a stainless-steel workpiece. Remember, stainless-steel is very difficult to cut because it is strong, durable and corrosion resistant. However, there are special techniques in place that can be used to achieve the cutting process.
Precautions Before Cutting Stainless Steel
The goggles will protect your eyes from heat, optical radiation, ultraviolet light, sparks and debris produced during the cutting process.
Gloves are part of the personal protective equipment and they protect from electrical shock, infrared radiation, abrasion and extreme heat.
The choice of boots and overall should be ones that will protect from heat, shock, sparks, infrared radiation and abrasion.
Prior training should be given to staff before they can handle any cutting tool to avoid accidents and unnecessary damages.
The workspace should be tidy, well lit, power cables kept properly, well ventilated and all flammable materials removed for safety.
There are various types of stainless-steels in the market and the type in use, will determine the type of tool.
Prepare Workspace For Cutting Stainless Steel
Ensure the work environment is tidy for easy movement around the place. That is, your workspace should be properly lit to ensure accuracy. Additionally, the power cables should be kept properly to avoid tripping on them and the room should have proper ventilation. Finally, all the flammable materials are removed from the working area.
Measure & Mark Stainless Steel
Measuring the stainless-steel workpiece for cutting can be achieved through a measuring tape. The measuring tape will help in estimating the section to be cut through.
Use a marker, mark the areas to be cut off. Marking will help to make accurate and precise cuts. There are various ways of marking a stainless-steel metal such as a permanent marker, a scribe, or a combining the two. Other ways of marking the metal include an engraver or a soapstone. If the cut is to be a straight line, then you can use a ruler or square to achieve a precise cut.
Cutting Stainless Steel Saw
Cutting Stainless Steel With Circular Saw
This tool is suitable for cutting large stainless steel sheet metals and they are handheld. A circular saw is easy to use and can freely move to enable straight and curved cuts. The circular saws work better when held with two hands for support and to guide the blade through the metal. This tool is used in a push away direction and the rear part is covered though a guard which surrounds the blade. A fixed guard covers the top of the blade and it has an additional handle to direct the cutting process.
Cutting Stainless Steel With Jigsaw
Jigsaw is a hand-held tool which is operated through a squeeze trigger designed in the handle. This tool is used for cutting metals and other materials such as wood and pipework. Here is how to cut stainless-steel metal using a jigsaw;
- Put on an appropriate PPE for eye, ear, feet and body protection.
- Measure and mark the workpiece
- Clamp the stainless-steel metal to the bench.
- Swich off the power and choose the type of blade to be used for that process and insert it into the tool.
- Check if all the settings are done properly and switch on the power
- Cut through the metal following the cutting directions.
- As the cutting is on, pause at some point and add drops of cutting fluid to avoid overheating
Cutting Stainless Steel With Band Saw
Band saw is a power saw that can be used for cutting various materials including metals like stainless steel. This tool has a long sharp blade with a continuous band containing toothed metal which is stretched in between wheels. Below is the procedure for cutting stainless steel with a bandsaw;
- Wear correct PPE
- Mark the line
- Choose correct blade
- Check the settings
- Connect power
- Cut through the metal following directions
Plasma Cutting Stainless Steel
When choosing the cut quality and the type of edge finish for your project, you must also select the correct gas type. There are two types of gases that can be used for plasma cutting – single gas cutting including air, oxygen and nitrogen. Dual gas cutting including nitrogen and water, hydrogen and nitrogen, argon and nitrogen.
For stainless steel metals that are less than 5mm in thickness you can use nitrogen or water for shielding gas. When dealing with stainless-steel more that 5mm and below 12mm in thickness, use F5 as plasma gas and nitrogen for shielding. For stainless steel of thickness 5 to 50 mm, it is recommended to use Hypertherm’s Vented Water Injection process.
When using plasma cutting stainless steel you should keep the following in mind;
- Ensure that you follow the cut directions provided in the manufacturer’s manual
- Make sure to avoid accumulation of dross during the cutting process by keeping a constant torch speed.
- Use a straight and long lead-in to help minimize the amount of slag produced during the cutting process.
- Ensure that the parts are completely cut by slowing down at the end to check if the cut is complete.
Laser Cutting Stainless Steel
This involves the use of high-energy and accurately focussed laser beams for cutting to produce accuracy and precision. However, it is difficult to cut stainless steel of thickness greater than 25mm using laser cutting stainless steel. Even though the initial cost for setting up a laser cutting stainless steel, the minimal waste on material makes it cost effective.
The types of stainless steels that can be laser cut include; ferritic stainless-steel, duplex stainless-steel, austenitic stainless-steel and martensitic stainless-steel. Some of the industries that use the parts cut through laser cutting include nuclear power industry, marine industry and architectural industry.
Why laser cutting stainless steel is to be chosen;
- Parts produced through laser cutting are highly refined.
- Laser cutting can produce parts that can be used for various industries.
- Another benefit is the various surface finishes that can be achieved through laser cutting.
- It does not need the presence of a shielding gas to carry out the cutting process.
The problem with laser cutting stainless steel is that there is high power consumption. Additionally, the procedure is also very delicate and must be handled with care. Also, laser beam should not get into contact with the body.
Waterjet Cutting Stainless Steel
This is the use of a cutter that involves a high-pressure jet stream of water for cutting. An abrasive waterjet cutting stainless steel works quickly and cutting can be achieved easily. Some benefits include;
- This process is preferred because it does not involve the risk of overheating; it is a cold cutting process hence no heat-affected zones.
- Another benefit of waterjet cutting is the fact that parts don’t have to undergo secondary processes.
- Waterjet cutting is very accurate and the metal is not distorted in any way.
- This is also the method suitable for cutting stainless steel metals that are thicker in dimensions.
- Waterjet cutting stainless steel can be used for large and small scale cutting of stainless steel.
Some of the disadvantages of waterjet cutting stainless steel include;
- The cutting time is a bit longer when using the waterjet for cutting stainless steel metal.
- Setting up a waterjet cutter is very expensive when compared to other cutting techniques.
- When the stainless steel is a bit thicker, the waterjet cutting can produce inaccurate cuts.
- Some waterjets are made with low quality orifices which sometimes end up breaking down during operation.
Other Stainless Steel Cutting Techniques
Shearing stainless steel is the cutting process that removes the unwanted part of a stainless metal sheet. The stainless steel is moved through the shearing machine where the blades aid in fracturing the metal into pieces. Shearing works with accuracy, minimizes material loss, and can produce high output very quickly.
Milling is mostly done with austenitic stainless steels because they have high work hardening rates with low chip breaking characteristics. When milling stainless steel there should be no rubbing created by the machine vibration. Stainless-steels can be milled through the use of tools made from high-speed steels and cemented carbides.
There are various ways through which stainless-steels can be machined or turned. Austenitic stainless steel can be turned through the use of sharp edges while duplex stainless steels, small entering angles. The available techniques that can be used for turning stainless-steel have various rules and guidelines to be adhered to.
A welder can also be used for cutting stainless-steel where it produces sparks at high voltages and fumes. When cutting through a welder a hot rod is made to move through the stainless-steel workpiece in line with the requirements. During this process, one must be wearing the personal protective equipment.
This is the process that involves cold forming where a strip of stainless-steel is cut and shaped through a die. The process applies forces to the stainless-steel metal to modify its geometry to make it suitable for formation. Die cutting can take place in three forms line, transfer and progressive.
Stainless steel is difficult to punch and may need tools that are made from harder materials made by using D2 material. No matter how hard the punching tool is, it wears out very fast or may need a lot of force and effort to remove the punches from the steel.
Types Of Stainless Steel To Cut
Austenitic stainless-steel contains low level of carbon in them with high level of chromium and nickel contributing to formability and corrosion-resistance. They are grouped into 200 and 300 series and can be used in industries like medical and automotive industries.
These steels are made up of up to 30% of chromium and are essentially non-hardenable through treatment by heat. However, they can be slightly hardened by cold rolling and are stronger than austenitic stainless-steel; can be used in hot-water tanks.
Martensitic stainless-steel is a magnetic steel made up of deposits of chromium and nickel and can be used for various applications. The stainless-steel material offers resistance to corrosion and can be hardened through heat treating to form a crystalline structure.
Applications Of Stainless Steel Cutting
Due to the strength and high corrosion resistance offered by stainless steel, it can be used for making parts such as reverse osmosis units.
Stainless-steel is used for making knives, cookers, countertops, dishwashers, fridges and many others.
Stainless steels offer strength, durability, and resistance to corrosion making them suitable for making bridge parts.
Tanks that are used for keeping corrosive substances like chemicals or acids and other products such as gases are made from stainless-steel.
People Also Ask:
Stainless-steels possess various properties that make them hard to cut;
Toughness- absorb energy during deformation.
Work hardening- get even harder when deformed
Heat generation- they can generate heat when deformed.
Laser cutting produces heat meaning that stainless-steel can be hardened by the heat. However, this depends on the type of stainless-steel in use because some will not harden while others will.
Stainless-steel offers various advantages like durability, corrosion resistance, strength, toughness, heat resistance etc. Stainless-steel can be used for various applications for instance in industries like automotive, marine, food and aircraft.
Stainless-steel is generally difficult to cut, however, there are a number of ways through which it can be done. Techniques such as laser, waterjet, plasma and saw cutting can be used.
Steel can be alloyed with countless number of other elements to make the various stainless-steel alloys including;
Overheating can create heat affected zones which appear different from the rest of the workpiece. When stainless steel is overheated, the hardness and strength are affected since it interferes with the microstructure of the metal. Overheating therefore, can destroy the stainless-steel and cause harm to the environment.