Sheet metal is more common in residential applications than you’d think. Replacing roof flashing, repairing HVAC ducts, and fixing ducts and gutters are just some of the projects where you can encounter sheet metal and in this post, you will learn how to cut sheet metal.
While cutting sheet metal is not a hard task, the thinness of this material makes it incredibly easy to bend, score, or gauge by accident when you’re manipulating it.
You can avoid this by selecting the right tool, and following the right steps. Depending on the type of cut you want to make, you can choose between using a circular saw, tin snips, a Dremel, or nibblers.
To cut sheet metal with any of these tools, you have to follow some general steps: prepare the material and your workspace by setting up your workspace, drawing the cutting line, making the cut, and removing the burrs.
Keep reading if you want to know all the details on how to cut sheet metal!
Tools and Supplies You’re Going to Need
No matter which tool you’re going to use, there are some common supplies you’re going to need to gather before you can start:
- Sheet metal
- Cutting tools (circular saw, tin snips, dremel, or nibblers)
- PPE (Personal Protective Equipment): safety glasses, dust mask, work gloves, and earplugs
- A wide, stable workspace
- Combination square
- Measuring tape
- Permanent marker
- Masking tape (optional)
Cutting metal always carries the risk of producing metal dust and fragments that can be dangerous for you, and those around you. For this reason, make sure there are no kids or pets around that can get injured.
Moreover, always wear safety goggles, leather gloves, and cover up with a good pair of steel-toe boots, long sleeves, and long pants for additional protection.
If you’re working with power tools such as a circular saw or an angle grinder, you’ll also need a dust mask and earplugs because they’re quite noisy.
All projects require that you prepare your tools and materials if you want to achieve professional results. Nobody wants messy cuts and uneven edges that you’ll have to spend extra time fixing. So, let’s get the cut right from the very beginning!
This is what you have to do to prepare for cutting sheet metal:
- Set up a sturdy, stable workbench that can hold the sheet metal you intend to cut.
If you’ve chosen power tools for this project, you can use a sawing table or a 4-foot by 8-foot sheet of plywood supported by a set of sawhorses as your workplace. This way, there won’t be anything directly below your cutting line that can block your blade.
- Place the sheet on top of the workbench and use a tape measure and a permanent marker to draw the measurements along the edges of the material. Use a combination square to connect the marks into the cutting line.
- This is an optional step, but we like to use masking tape on both sides of the sheet metal, lining it up with the cutting line we’ve drawn. This way we ensure a cleaner cut and prevent metal chips from scratching the material.
- Secure the sheet with adjustable clamps so that it doesn’t move as you cut it.
- We recommend measuring twice just to be completely sure that everything is correct and as precise as it can be.
And that’s all. The boring part is over. Preparing sheet metal for cutting is incredibly easy, so we believe it’s worth taking some extra minutes to do it.
How to Cut Sheet Metal Using a Circular Saw
For making simple lines or long, straight cuts in sheet metal, a circular saw is a great option. This tool can be very efficient and make quick work of your material when it’s equipped with a sharp blade that’s specially designed for this job.
Working with a circular saw can also be very loud and produce large amounts of dust and metal fragments, so make sure you’re wearing your PPE.
To cut sheet metal with a circular saw, you should:
- Secure the blade and adjust the blade guard so that it’s between the tool and your body.
- Turn the saw on and allow the blade to reach full speed.
- Grabbing the saw with both hands, lower it slowly onto the cutting edge you’ve marked.
- Push the blade forward with your dominant hand along the marked line. You need to apply light pressure to the saw, but only to guide the blade. Let the circular saw do the job for you, and don’t force it through the metal so you can avoid kickback.
- Keep pushing until you reach the end of the line.
The entire process shouldn’t take longer than a few minutes. So, don’t try to push the circular saw to go faster, and don’t try to change the blade’s direction because it can make you lose control of the tool.
How to Cut Sheet Metal Using Tin Snips
Tin snips are an excellent option if you want to make curved cuts. Also known as aviation snips or compound snips, these scissor-like tools are color-coded based on the direction that you need to cut.
Yellow-handled snips are used to cut a straight line, red-handled ones are designed to cut to the right, and green ones to cut to the left.
After selecting the one for your particular project, use the tin snips as you would a pair of regular scissors:
- Hold the side of the material with your non-dominant hand to keep it in place.
- Align the blades of the snips with the line you want to cut, placing the upper blade of the tin so that it’s touching the sheet metal.
- Press on the handles to make a cut and release them to free them.
- Push the snips forward, and repeat the process to make short, quick cuts along the marked line.
Using tin snips can be a bit slow, and since it also requires some effort, we don’t recommend using them to make long cuts or on large sheets.
How to Cut Sheet Metal Using a Dremel
Dremel blades are so small and easy to maneuver, which makes them ideal for making short, detailed cuts in sheet metal that are either straight or curved.
To cut sheet metal using a Dremel, you should do the following:
- Turn your dremel on and set it to a medium or high speed.
- Slowly lower the dremel onto the metal and press the blade against it.
- Use firm pressure to dig into the surface of the material until you achieve the ideal depth of your cut.
- Move forward along your marked line until you reach the end.
Important safety note: If you notice smoking coming from the Dremel, it typically means that the pressure setting is too high. Turn the tool off and set it to a lower setting. If the smoking persists, turn it off and contact the manufacturer.
How to Cut Sheet Metal Using Nibblers
Nibblers are specially designed for cutting sheet metal with no distortion and higher accuracy. They can be used to cut curves and make thin, short cuts, and other specialty cuts. They’re available as attachments for an electric drill or as a separate power tool so that you can choose the one that works best for you. Bear in mind that nibblers are rather expensive and unsuitable for making long, straight cuts.
To cut metal sheet metal using nibblers, you have to push the tool forward along the cutting line you’ve drawn, starting at the edge of the material. To avoid bending the sheet metal, keep the nibblers parallel to the metal.
Cutting metal can leave ugly burrs behind, no matter which tool you use. So, run a metal file along the edges to clean them up and remove the burrs.
You can also use 220-grit sandpaper to smooth the edges and then, switch to a finer grit for the final touches. To go a step further in achieving the best look, use a polishing pad to remove any remaining dust and buff out the shine.
Learning how to cut sheet metal can come quite in handy in many projects around your home. In this piece, we’ve covered the most common types of cuts, and given you four different options that you can use depending on which cut you want to make.
It’s easy to do, as long as you’re patient and use the right tools. Just remember to prepare the sheet metal and your workspace, and to wear your PPE, and you’ll be cutting sheet metal like a pro in no time!