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Although most people immediately think of a jigsaw as being used to cut wood, you might wonder whether it’s capable of cutting metal too?
Jigsaws are able to cut straight and curved cuts in metal when fitted with the appropriate blade. The blade must be bi-metal with a tooth count between 18-24 teeth per inch. Bi-metal blades cut depths of 19/32 inch (15mm) in steel and 1 inch (25mm) in aluminum. For tougher metals, a higher tooth-per-inch count is needed.
Later on in this article, I show you how to successfully cut metal using your jigsaw, with some additional tips thrown in that you won’t want to overlook. But first, let’s take a closer look at metal-cutting jigsaw blades.
The two important features of metal-cutting jigsaw blades
Jigsaws are a great choice for cutting metal; however, it’s vitally important to use a suitable blade. The blade material and teeth per inch are what is most important, so here’s everything you need to know.
If a jigsaw is going to be used to cut metal, then the blade used needs to be far stronger than a standard blade used for cutting wood. The most suitable blade for cutting metal is a bi-metal blade, which is made from a combination of high-carbon and high-speed steel.
The teeth are designed to be able to cut tough metal as they are made from high-speed steel, with the high-carbon steel body providing flexibility.
This combination makes it suitable for cutting tough metal and hardwood. Another benefit is that these blades last around ten times longer than ones that are made from single-carbon steel blades.
Teeth per inch count
One of the most important factors to consider when choosing a jigsaw blade to cut metal is the number of teeth that the blade has. The amount of teeth in a blade is measured in teeth per inch (TPI), and tougher materials such as metal need a blade that has a higher TPI than softer materials.
Teeth per inch is used to determine the cutting speed of a blade. Blades that have fewer teeth produce a much faster but rougher cut, while blades with a higher TPI cut much slower and give a much smoother finish.
Blades that have a TPI of between 18 and 24 are the most suitable for cutting metal. Some blades have curved teeth, which provide added strength and improved performance.
How important is blade length?
There is no set length that is ideal for a jigsaw blade, but you should always make sure that the length of the blade is appropriate for the cutting area of the metal.
Regardless of what length your blade is, you should always ensure that there is at least 25mm of legroom when you are cutting in order to protect your hands from the bounce-back of the blade.
What type of metal does a jigsaw cut?
A jigsaw that is fitted with a bi-metal blade can cut several types of metal, including ferrous and non-ferrous sheet metal, aluminum, and mild steel. However, for other types of metal, the jigsaw will likely need a blade that has a greater TPI count.
Jigsaws are not able to plunge-cut in metal; however, you can drill a hole into the metal in order to insert the blade and then proceed with cutting as usual.
What thickness of metal can a jigsaw cut?
The thickness of metal that a jigsaw can cut will depend on the strength of the blade and the TPI. A jigsaw can usually cut through 19/32″ (15mm) steel and 1″ (25mm) aluminum.
If you have a more robust professional jigsaw paired with a blade that has 20 TPI or more, then it should be possible to cut non-ferrous metals up to a thickness of 1 3/16″ (30mm).
How to cut metal with a jigsaw
Before you cut any sheet metal with a jigsaw, you should make sure that you have a sacrificial sheet of plywood underneath for support. This is so that the metal will stay flat while you are cutting and also reduce the amount of vibration that is created in the process.
If the sheet of metal that you are cutting is particularly thin, then it’s a good idea to also place a sheet of plywood on top for added support.
Before beginning, make sure you’re wearing the correct safety gear. These include gloves, ear defenders, safety goggles, and work boots with reinforced toecaps.
1. Clamp the metal
The first thing you should do is securely clamp the wood and the metal to the workbench you are using.
2. Mark your cutting area
Next, you need to mark your sheet of metal (plywood if it’s on the top) where you want to make the cut.
3. Position the jigsaw
You should line the blade of your jigsaw up with the line you have marked. The front of the shoe on the jigsaw should be resting on the front edge of your metal or plywood.
4. Make the cut
Choose a low-speed setting and then power on your jigsaw. Once the blade has reached its full speed, you can then push the jigsaw slowly along the line that you have marked to make the cut.
5. Apply cutting oil
As you cut along your line, you should apply cutting oil to the blade every so often. This will keep the blade and the metal that you are cutting nice and cool.
6. Tidy up the edges
When you cut metal with a jigsaw, you will often find that it has left rough or sharp edges on the metal. Use aluminum oxide sandpaper to tidy up the edges and create a smooth finish.
Expert tips for a superior cut
- Insert the blade with the power supply off, and check that it’s secure and tightened properly. While you are doing this, you should also check that you have the jigsaw set with the correct settings for cutting metal, such as checking that the blade is in the vertical position that is used for cutting metal, rather than angled forward which is the setting for cutting wood. Also, if the metal you are planning to cut is something that will mark easily, then you can cover the shoe of the jigsaw with masking tape so that the metal sheet is protected. Once you are certain that you have selected the correct settings, you can turn the power on, making sure that you keep your fingers away from the trigger while you do so.
- Never attempt to cut without first marking the cutting line. It’s a good idea to use a permanent marker as it will make your cutting line clearly visible. If you need to cut in a straight line, then make use of a ruler or a piece of wood. If you plan to make a curved or circular cut, use a pattern.
- If you are beginning your cut at the edge of the material, then press the shoe of the jigsaw down firmly on the material without allowing the blade to come into contact with the metal at this point. You can gently press the trigger switch and push it forward onto the material once the blade is moving at full speed. As you are cutting, always allow the blade to do the work of making instead of forcing it. If your cut starts away from the edge of the material, then you will need to drill a hole into the metal so that you can insert the blade and then continue as described above.
- You should move your clamps and rotate the material as necessary in order to keep the jigsaw in the best position. This will help you to achieve an accurate cut.
- The exposed areas on sheet metal that have been cut are often prone to rusting (especially galvanized iron). If you plan to store the metal after cutting, you need to make sure that the room is dry. You can also coat the edges in oil to prevent rusting.