What should I use to cut through metal?

I tried cutting metal on my horrible, antique, guard-less, drill powered circular saw, that had over a millimeter of play in the blade (arbor).

And to my surprise, it worked much better than I had expected - so well I bought an actual circular saw. I bought a corded Worx mini 710w circular saw. (If you're interested in this saw, I have a detailed 5-min review video on it)

First, I tried using my circular saw to cut aluminum, the same way I would cut wood - and it worked perfectly! It cut very fast (~30x faster than hacksawing), and as long I was careful, it left a smooth edge, even on a solid aluminum rod (see picture 5).

Next, I also tried cutting brass flat bar. Cutting it took more time, but it also worked very well.

After that, I moved on to steel, knowing it would be the hardest to cut. I adjusted the blade height and cut successfully through steel flat bar. Next, I tried cutting through stainless steel, and the blade just wouldn't budge, and I didn't want to push it through with too much force. The stainless didn't feel hardened, but suspecting it had damaged the teeth, I tried cutting through thin aluminum angle, which it cut through easily.

I quickly built an improvised chopsaw using an door hinge (don't try this!), and tried to cut through rebar, failing multiple times, and despite securing it properly, the rebar flew off while cutting, which I caught on a slow-motion camera - it's in the video! I didn't know if it would cut all the way through, but expected it to cut at least half way, yet it didn't budge. I have a few theories for why this happened, since I've seen rebar being cut easily with a carbide tipped blade in the past. The blade was damaged, the $3 carbide tipped blade I bought was very cheap and had low quality carbide teeth, they didn't have the right geometry, I was cutting at the wrong angle, and the hinge had way too much play in every direction - my fault.

This, as expected, destroyed the blade, breaking off half of the carbide teeth, so I moved on to the next step - cutting sheet metal! Vibrating and rattling material can break off teeth, so I decided to try something new. I clamped the sheet metal between two sheets of plywood, which I clamped to my workbench, effectively eliminating the possibility for any vibrations could ruin the saw blade. To my utter surprise, my circular saw managed to cut through it without stalling the motor, though I could clearly hear it was struggling, definitely something I will be repeating in the future.

Most circular saws are larger than mine, and using a small blade in a large circular might theoretically not be a bad idea because small blades are supposed to spin faster, and larger circular saws are supposed to spin slower. The slower the speed, generally the longer the blade will last. This is measured in FPM. Always follow the instructions and do your own research!

I reached out to two professionals with my questions, and here are their replies:

John Heisz: "Here's what experience has taught me: the deeper the blade is, the faster (and cooler) it will cut, but the greater the risk of snagging on the metal. - with the blade shallow, it will cut slower, run a bit hotter but is much less likely to catch on the steel. If you are cutting metal that's thick, (1/4" or more) it's better to have less teeth cutting the metal at a time, since the teeth can't snag as easily. So deeper is better in that instance." Though John has deleted his reply for an unknown reason.

Wide Vision Metal Fab started using woodworking blades originally because they were significantly cheaper than metal cutting blades, and claims they last the same amount of time: "I never had [carbide] teeth fly off or explode, but they could chip if in a bind. But the "correct" blades also can chip when in a bind. About the only difference I could tell between the blades was the metal chips. They seemed to be cooler and smaller with the steel cutting blade, which makes sense given the geometry of the teeth, and that wood is softer, which means more can be removed by each tooth." WVMF has since stopped using woodworking blades because they were too small by a fraction of an inch, and the price of metal cutting blades has decreased.

I didn't ask, and none have advocated for it - so try it at your own risk. If you have experience in these subjects, I'm curious if you have any recommendations regarding lubricating the blade, using diamond blades, and your overall experience.

In addition to standard circular saw best-practices and common sense, stay safe!:

• Always use safety glasses! The blade shoots tiny pieces of metal everywhere, consider also wearing a face shield
• Never remove the blade guard from your circular saw.
• Use a blade with as many teeth as possible. I used a 4" (110mm) 40 tooth blade. Larger blades should only be used if they have more teeth.
• If the blade suddenly explodes, will you be in the line of fire? Make sure your face, hands, legs, other people, or any windows won't get hit, and always stand to the side.
• Always make sure that the material you're cutting is not hardened steel. Try filing off a bit with a file, if the files slides off without its teeth biting into the material, it's hardened and should not be cut with a carbide tipped blade. Cutting hardened steel can cause the teeth to chip, sending small, sharp pieces of carbide everywhere very fast - and it the worst case it can cause the whole blade to explode.
• Don't overtighten the bolt that holds the blade.
• Don't use a blade with damaged teeth, inspect it before each use.
• Don't put a carbide tipped steel blade in a saw made for abrasive discs (the opposite)
• I've seen carbide tipped blades with large slots (I believe these are for cooling and reducing sound), and would avoid using them because they're likely more prone to bending sideways.
• If you plan on using yours a lot, I recommend investing in a proper "cold cut" metal cutting circular saw that's built for the job, with adequate RPMs and proper chip collection. Check out Milwaukee and Evolution.

Learn about the best metal cutting tools, as well as the most suitable methods for cutting common materials like metal sheets, studs, and metal pipes.

The selection of ideal metal cutting tools mainly depends on your workpiece quality, quantity, and your experience. A different metal cutting tool is required for different types of cut, for example, hole saw for a circular cut, chop saw for a straight cut, and rotary tools for precision and a small cut.

Today, we will cover all metal cutting tools and their works so you can choose the best one according to your needs and applications.

Read: 7 Best Ways to Cut Metal Fast

Best Power Tools to Cut Metal

Power tools are used for almost all metal fabrication and industrial workings. These cutting tools are required to perform numerous tasks such as grinding, polishing, drilling, cutting, sharpening, and sanding of metals.

Following are the most typical metal cutting power tools.

1. Angle Grinder

An angle grinder is a standard metal cutting tool for using cut-off wheels.

An angle grinder or hand grinder is one of the most important metal cutting tools. The standard 4-1/2" cut-off wheel is a widely used disc for angle grinders. You can also customize wheel sizes according to needs.

Angle grinder cuts metal fast and efficiently. Removing rough cuts, weld spatter, and rust is common applications of an angle grinder.

Pros

• Highly versatile tool

• Capable to work on small areas

• Compatible with different cutting wheels and material surfaces

Cons

• Not good to obtain fine and finished cuts

• High pressure can break wheels

• Irritating noise and kickback

2. Reciprocating Saw

Reciprocating Saw for metal cutting

A reciprocating saw also known as an oscillating saw is the most common and useful metal cutting tool. It is capable of cutting metal fast and efficiently. Reciprocating saws are among the most powerful and aggressive saws. Reciprocating saw tool works with standard metal reciprocating saw blades. You can use it to cut through metal sheets, wood, PVC, and pipes.

Pros

• Cuts through almost anything

• Powerful and fast cutting

• Perform a number of functions

Cons

• Quite rough and inaccurate

• Its large blade can cut wires

• No smooth cuts

3. Circular Saw

Circular Saw for metal cutting

Circular saws are one of the most commonly used power tools nowadays. Circular saws are capable of cutting metal, wood, hard steel, stone, and ceramic tile with a TCT saw blade.

Pros

• Provides clean cut-through metals

• Easily available and accessible tool

Cons

• Can't cut curves

• Saw blades are expensive & break easily

• Noisy tool

4. Hole Saw

Hole saw connected to drill

Hole saw cutters or hole cutting tools are made to be extremely tough to cut metals. They are capable to resist high temperatures produced by cutting through a number of popular metals including stainless steel. Bi-metal 5 inch hole saw is ideal for creating holes in timber and wood sheets. Apart from the metal hole saw can easily cut through wood, tile, concrete, and glass.

Pros

• Multipurpose cutting tool

• Cuts a perfect circle

• Less expensive

Cons

• Not a versatile tool

5. Cut-Off Tool

This metal cutting tool is similar to an angle grinder and works with cut-off wheels. Cut-off tools are ideal to cut stainless steel, carbon steel, aluminum, and other metals for general purposes. They are designed to provide a quick and accurate cut, also last longer and perform better than any traditional tool.

A cut-off tool is useful to work in small areas where other large tools can not work. But, this tool can not cut through thicker materials.

Pros

• Compact and easy to handle

• Can work in narrow space

• Ideal for removing weld splatter

Cons

• Too small for more extensive applications

• Can’t cut through thick material

That was all about metal cutting tools and power tools for metal cutting.