Saw Blade Types For Cutting Metal Roofing

There are several ways to cut metal roofing, and the best method depends on the tools you have available and the type of cut you need to make. If you're cutting corrugated metal roofing, you can use a circular saw equipped with a metal-cutting blade, an angle grinder with a metal-cutting blade, sheet-metal nibblers, or sheet-metal shears, which don't produce sparks or metal shavings. If you're cutting straight across a sheet, tin snips or power shears are a good option. For longer cuts or when cutting multiple sheets, a circular saw or angle grinder will be quicker, but they produce more noise and debris. You can also use a nibbler (either as a separate tool or as an attachment for an electric drill) to make rounded cuts, such as cutting a hole for a vent pipe.

Tin snips for thinner metal

Tin snips are a great option for cutting metal roofing, especially if you're working on a DIY project and don't have access to power tools. They are a hand tool similar in appearance and function to scissors and are best used with 29-gauge or thinner panels; anything thicker will be hard to cut. They also work well for shorter cuts.

Tin snips come in different varieties, depending on your needs. Here are some of the most common types:

• Straight-cut tin snips: These have straight blades and are typically used for making straight cuts. They are ideal for working on sheet metal roofing. Look for yellow handles to identify this type.
• Offset tin snips: These have right- or left-angled blades, making them more manoeuvrable than straight-cut tin snips when you want to make circular or angled cuts. Offset tin snips are typically colour-coded: green handles indicate a clockwise cut, while red handles indicate a counterclockwise cut.
• Vertical tin snips: Also known as right-angle tin snips, this type has blades set at a 90-degree angle to the handles, making them ideal for tight spaces.
• Duckbill-pattern tin snips: Also known as trojan-pattern snips, these have blades that taper down from the pivot to the tip, making them suitable for cutting curves and circles. They are a lighter-duty option that can cut up to 25-gauge mild steel.

When using tin snips, it's important to take the proper safety precautions. Wear protective gloves, as the cut edges of the metal will be sharp and can cause deep cuts if you slip. It is also recommended to wear eye protection to shield yourself from any flying shards of metal.

To cut metal with tin snips, follow these steps:

• Mark the cutting line: Use a marker pen to mark the desired cut line on the metal. This will make the cutting process simpler, especially if you need to manoeuvre and move the metal during cutting.
• Secure the metal: For larger pieces, you may need to clamp the metal to your work surface. For smaller pieces, you can simply hold it in place.
• Open the tin snips: Open the blades as wide as possible and nestle the metal deep into the jaws of the tin snips.
• Cut the metal: Start cutting along the marked line, applying firm and steady pressure to the handles. Make sure the metal is pressed snugly against the jaws of the tin snips throughout the cut. Work slowly and carefully to ensure a straight and smooth cut.

Metal shears for thicker metal

Metal shears are a great option for cutting thicker metal roofing. They are power tools that can cut through thicker metal panels more easily than tin snips and produce better cuts.

There are a few different types of metal shears that can be used for cutting thicker metal:

• Electric shears are similar to tin snips but are electric-powered, making them ideal for cutting thicker metal sheets. They are faster and produce better-quality cuts than tin snips. Electric shears are a good option if you need to cut up several metal sheets in a short amount of time.
• Pneumatic shears are another option for cutting thicker metal. They are similar to electric shears but are powered by compressed air instead of electricity.
• Compound nibbler shears provide more leverage for cutting thicker metals. They are typically hand-operated and use a compound mechanism to cut through thicker metal.
• Throatless shears are designed for cutting intricate patterns and shapes in thicker metals. They do not have a "throat" or feeding component, so the metal can be moved around freely to make straight, round, or irregular cuts. Throatless shears are typically used for cutting thinner metals, but a sharper hardened steel cutting blade can be used for thicker metals.
• Alligator shears are hydraulically powered and are typically used for rough cutting of pre-finished metal stock. They are simple and cost-effective but may not produce smooth finishes.
• Bench shears can be powered hydraulically or pneumatically and are used for cutting thicker-walled or stronger metal stocks. They can produce rough or smooth edges, depending on the configuration. Bench shears are considered mechanically advantageous due to their compound mechanism, which allows them to cut through a variety of metal thicknesses and types.

When using metal shears to cut thicker metal roofing, it is important to take the necessary safety precautions. Wear safety gear such as goggles, a face mask, thick gloves, and earplugs to protect yourself from metal dust, fragments, and loud noises. It is also important to securely clamp the metal sheets to a stable surface before cutting to ensure accuracy and prevent injuries.

Circular saws for cutting multiple sheets

Circular saws are a great option for cutting multiple metal roofing sheets quickly and efficiently. Here are some tips and guidelines for using a circular saw to cut metal roofing:

Choosing the Right Blade:

• Select a metal-cutting blade designed specifically for cutting sheet metal or metal roofing.
• Opt for carbide-tooth blades, which are more expensive but tend to last longer.
• Choose the appropriate blade size for your circular saw. A 7-inch blade is standard for most circular saws, while a 4-inch blade is suitable for an angle grinder.

Safety Precautions:

• Always wear protective gear, including goggles, a face mask or respirator, earplugs, long sleeves, and gloves, when using a circular saw.
• Secure your work area to prevent children and pets from wandering in.
• Unplug tools and store them safely when you're finished.
• Sweep the area to remove metal fragments and debris that could cause injury.

Cutting Process:

• Place the roofing sheets on a flat, stable surface, such as a workbench, with the underside facing up to make marks more visible and cutting easier.
• Measure and mark the areas you need to cut with a tape measure and a permanent marker. Double-check your measurements to avoid mistakes.
• Secure the sheets with adjustable clamps or weights to prevent movement during cutting.
• Fit your circular saw with the chosen metal-cutting blade.
• Line up the blade with the cutting guideline, ensuring you approach at the correct angle.
• Cut along the guideline at a slow and steady pace, applying gentle pressure to control the saw.
• If the saw stops working, turn it off and complete the cut from the other side of the guideline.

Using a circular saw with a metal-cutting blade is an effective way to cut multiple metal roofing sheets. However, always prioritize safety and follow the manufacturer's guidelines for your specific saw and blade.

Angle grinders for cutting single sheets

An angle grinder is a great tool for cutting corrugated metal roofing sheets. However, it is not recommended for thin sheet metal roofing as it can burn the paint finish and leave a hazardous sharp cut edge. Angle grinders are also not ideal for cutting corrugated iron, as there are safer and faster tools for the task.

If you do decide to use an angle grinder, it is important to take the proper safety precautions. Wear gloves and a welder's mask, and work in a well-ventilated area, as the fumes emitted by corrugated metal are toxic. You should also wear long sleeves and pants for added protection against sparks.

When using an angle grinder, be sure to use a continuous diamond wheel. This type of wheel will keep its shape and sharpness when working with corrugated metal. Standard continuous wheels can also be used, but they will wear down more quickly.

To cut the metal roofing sheet, set the sheet flat on a work surface or sawhorses. If the metal is thin, weigh it down with a heavy object or stack several sheets together. Tighten the grinder blade and put both hands on the grinder handles. Turn on the grinder and hold it at a 45-degree angle towards the metal. Slowly push the grinder across the path you are cutting, allowing the excess metal to fall freely to the floor.

Angle grinders are best for making freeform and round cuts, as they provide more control than other tools. They also leave a smooth edge, as the side of the grinder is designed to cut through materials.

Nibblers for specialty cuts

Nibblers are ideal for cutting corrugated sheet metal. They are also useful for cutting metal roofing, as well as automotive bodywork, which usually requires perfectly clean cuts. They can cut all types of roofing iron, copper, plastic, and even lightweight aluminium.

Nibblers are perfect for cutting intricate shapes quickly. They can cut sheet metal around corners, angles, and intricate shapes with precision. This is why they are the tool of choice for professional roofers.

Nibblers are also great for cutting corrugated metal sheets on an angle. The cutter has to go up and down over each corrugate, and nibblers are good at this. Shears or tin snips would be slow and messy.

Nibblers are also useful for sculptors and creative metalworkers who need to cut patterns out of sheet metal. They can negotiate tight curves easily, meaning an experienced operator can wield them with a considerable amount of control, much like a jigsaw.

Nibblers are not suitable for cutting extremely fine lines like hand shears or snips. They also produce a lot of waste in the form of tiny metal chips, which can cause injury and damage if not carefully contained.

There are a few different types of nibblers to choose from:

• Electric nibblers: These are the best option for cutting sheet metal and roofing and result in fast and clean cuts. They are more portable than pneumatic nibblers but less portable than cordless nibblers.
• Cordless-powered nibblers: These are a convenient option if you're working in a remote area without access to a power outlet. However, they tend to be underpowered compared to corded nibblers, and you need to ensure the battery has enough charge.
• Compressed air nibblers: These nibblers are powered by compressed air and are fairly inexpensive if you already have a compressor. However, compressors are very loud and the hose can get in the way.
• Nibbler drill attachments: These are a cheaper alternative to electric nibblers and are suitable for DIY enthusiasts or those only making a few cuts. They can be used with guides for greater accuracy when cutting perfect circles or straight lines.
• Manual hand nibblers: These cut extremely slowly and are only suitable for the smallest metal-cutting jobs.

When choosing a nibbler, consider the brand, cutting depth, portability, price, and whether the cutter head is durable and replaceable. Makita and Hitachi are known for making high-quality, durable nibblers that can cut through a wide variety of materials.

Frequently asked questions