Today I completed a comparison between cutting 4-inch cast iron pipe with a reciprocating saw and an angle grinder to see which one was the best and the fastest. As a contractor and plumbing handyman in Atlanta, I do get requests for cast iron drain pipe repairs.
I recently completed a repair and I reminded myself that I needed to save a piece for this comparison. We will be cutting through 50+-year-old 4-inch cast iron drain pipe, complete with all the old nastiness inside (most of it is dry by now, but still).
Milwaukee vs Dewalt Tools
I am using a Dewalt corded angle grinder. This one is medium sized (its actually pretty big, but it’s not the ginormous one) and I have outfitted with a metal cutoff wheel. The reciprocating saw that I will be using is available here on Amazon.
I have everything set up on the edge of the woods in a picturesque setting and we are just about ready to begin. I will need to be able to stabilize the piece of cast iron that I will be cutting. In order to this, I will sit the section of cast iron pipe on my handy portable fold-up table. I will cut through the cast iron several times with each tool for time.
There are other tools that will cut cast iron, I am testing these two because they are tools that contractors, handymen, and homeowners commonly own.
The first time that I cut through the cast iron using the reciprocating saw it took me nearly 1 minute. I was cutting using basically only on hand. For the next round, I used two hands, so that I could better stabilize the pipe and so that I could apply more pressure and move the same more efficiently.
The second time trial resulted in a much lower time than the first with a time of 25 seconds. I learned my lesson, and I will use two hands to cut the third time as well. In the 3rd time trial, my time was nearly identical to the second run. I think I’ve done it about as fast as I can. Be sure to take a look at the reciprocating saw blade I used here on Amazon.
Now its time to move on to the angle grinder time trials. I set the cast iron pipe up on the table and I will stabilize it with my left hand as I cut. This is actually my first time cutting cast iron with an angle grinder. After i begin to cut the cast iron in my first trial run I notice sparks and dust flying everywhere. I stop for a moment because I realize that I am going to need additional (personal protective equipment).
Best Grinder Blade for Cast Iron
I pause the time trials and put on a long sleeve shirt, a pair of safety glasses, and respirator. Now I’m back. Let’s go! As I begin cutting with the angle grinder, it does a good job of cutting through the pipe. I then begin to move the grinder back and forth along the initial cut. As the cut seam expands and I get close to 180 degrees around the pipe, I have to roll the pipe over on the table in order to access the other side of the pipe. As I cut completely through the cast iron pipe for the first time with the angle grinder I look at the clock and it has taken me almost the same amount of time that it took me the first time with the reciprocating saw.
I’m optimistic about the second round because I think I can improve my cutting time with a few modifications to my technique. In the second time trial, my time drops, but only slightly. Its nowhere near where I had hoped. I set up for the third round to try and get closer to the reciprocating saw times. I cut through the pipe in the same way that I did the first two times and I got pretty much the same results.
In desperation, I decided to try a 4th time trial with the angle grinder. This time I am going to set the pipe on the ground with the end I’m going to cut pointing up. After two valiant attempts, I just can’t get it done. This one is a wrap!
Reciprocating Saw Vs Angle Grinder
After using both tools to cut cast iron back to back, I have a very clear understanding of the differences between these two tools.
The reciprocating saw allows you to cut straight through the pipe the way that you would cut butter with a butter knife. However, because I was budget conscious, I opted for the 6-inch blade and I did have to modify my cutting technique to keep the end of the blade from hitting the inner wall of the pipe during the cutting process.
This issue can easily be eliminated by purchasing the longer version of the blade either in the 9-inch version or the 12-inch version are both available on Amazon. I should add that I did adjust the guard on the front of my reciprocating saw and that seemed to pretty much eliminate the problem. However, cutting through 4 inch cast iron pipe is pushing the 6-inch blade to its limits due to its short length.
Being able to cut straight down through the cast iron is a major advantage because you are able to make a straight cut a lot more easily and you never have to change your sight line during the cut.
I also noticed that applying pressure to the reciprocating saw definitely allowed me to cut the cast iron faster. Cutting the cast iron with the reciprocating saw made very little dust, and the dust that it did make just fell to the ground.
Cutting with the reciprocating saw did not create any sparks.
Once I made my initial plunge cut with the reciprocating saw blade, the saw was very easy to control and pretty much cut in a straight line on its own after that.
Even Though I wasn’t paying very close attention, but I don’t recall the pipe getting very warm, as I cut it with the reciprocating saw.
Cutting Cast Iron with the Angle Grinder
After using the angle grinder to cut cast iron I have some key takeaways. As you can see in the video, I had to change into a long sleeve shirt when I began cutting with the angle grinder because of all the flying sparks. I also had to put on goggles and a respirator because of all the dust that the angle grinder created as it cut. And because it works with a spinning wheel, the grinder was compounding the dust issue by sliding it into the air.
I also noticed that there is a distinct difference between the way these two tools cut. The reciprocating saw with the carbide tipped blade literally cuts through the cast iron. The cutoff wheel on the other hand basically runs through the cast iron pipe. I noticed after my time trials that the spinning disc on the angle grinder was at least an inch smaller.
As I cut with the angle grinder I also noticed that the pipe was heating up.
Perhaps the most difficult part about cutting the cast iron with the angle grinder was trying to keep the blade going in a straight line and trying to rotate the grinder around the circumference of the pipe as I cut. This is because the angle grinder can only cut through half the pipe at most without having to rotate the pipe 180 degrees or flip the saw to the other side of the pipe.
Based on this experience, I would only use the angle grinder if I didn’t have access to a reciprocating saw and I was going to be cutting in an area where dust was not an issue.
Reciprocating Saw Blade for Cast Iron
Another big difference maker was the blades. I used a carbide tipped reciprocating saw blade designed for cutting cast iron and thick metals. Available here on Amazon. This blade is a significant improvement over the diamond grit blades that have been used to cut cast iron for years. This blade actually cuts through the cast iron as opposed to the diamond grit blade, which rubs through the iron much like the angle grinder cut-off wheel.
If the carbide tipped blade was not an option I would still select the diamond grit blade and reciprocating saw over the angle grinder and cutoff wheel. The reason is that the reciprocating saw is easier to control, and gives you the flexibility to cut in more areas. And even though they work with the same grinding principal, the reciprocating saw will create less dust because the saw moves back and forth instead of spinning.
What is the best Sawzall blade for cast iron pipe? ›
Our Diamond Grit SAWZALL® TORCH™ blades are ideal for cutting cast iron, hard tile, masonry and other abrasive and hard materials. The diamond grit delivers you up to 30X longer life than standard blades and a thick, rigid blade body resists bending and fracturing for added durability.What is the best way to cut iron pipe? ›
Heavy-duty steel pipe and tube cutters are usually the easiest to use, but for tight spaces, an angle grinder or reciprocating saw may be needed. When using a metal pipe cutter, align the tool around the marked place on the galvanized pipe and rotate so that the wheel cuts deeper into the pipe until severed.What is the best grinding wheel to cut cast iron? ›
Silicon Oxide Grinding Wheels
Silicon carbide wheels are good for harder alloys but also for materials on the soft side such as copper, fused alloy steels or cast iron.
The fastest way to cut cast iron pipe is with a reciprocating saw and a carbide-tipped blade with 8 teeth per inch (TPI) spacing.What do you need to cut cast iron pipe? ›
- Meterstick/Ruler/Chalk/Crayon – To Measure The Pipe.
- Marker/Pencil – To Mark The Cut.
- Hacksaw/Reciprocating Saw/Angle Grinder/Snap Cutter – To Cut the Pipe.
- Sandpaper/Belt Grinder/File – To Deburr The Pipe.
- Cut-Resistant Gloves.
- Eye Protection (Face Shield Prefered)
- Ear Protection.
Pipe cutters are tools used for slicing or cutting pipes. They are commonly used by plumbers due to their reliability and efficiency. In addition to providing clean, professional-quality cuts, pipe cutters are often more convenient, fast, and easy to use than alternatives such as hacksaws.Can an oscillating tool cut cast iron? ›
The OSC114C (OSC114C-2 for two pack) carbide tip blade can cut both metal and wood, including harsh applications like fiber board, cement board, plaster and lathe, ceramic tile, nails, bolts, screws, sheet metal, copper pipe, cast iron and hardwoods. The 1-1/4 inch blade width helps the user speed through long cuts.Can you cut cast iron pipe with a torch? ›
In addition to being cut with an abrasive pipe saw, a rotary wheel cutter, a guillotine pipe saw, or a milling saw, Ductile Iron Pipe can also be cut with an oxyacetylene torch if recommended by the pipe manufacturer.What kind of grinder blade will cut cast iron? ›
The angle grinder is probably going to be your best bet for making cuts in the cast iron piece. The grinder offers the best option for getting the cuts where you want them and keeping them relatively smooth.Can you cut cast iron with a cutting wheel? ›
The wheel's long lasting durability maximizes cutting even in extreme applications such as rebar, angle iron, cast iron and steel bar.
Can I cut cast iron with a Dremel? ›
To keep the disc life as long as possible, do not apply excessive pressure and do not exceed the RPM limits. This cut-off disk can be used on different metal types, like aluminum, copper, cast iron or even hardened steel.How do you cut a large diameter cast iron pipe? ›
When you have larger diameter iron or steel pipe to cut or trim, a rotary cutter is a great solution. For cutting pipe in place, a rotary cutter makes the task much more manageable, and helps to reduce the down time that removing and replacing the pipe may create.How do you cut a pipe without a pipe cutter? ›
People use hacksaws to cut copper pipe because they typically have them lying around. If you have one, and you don't need to access the pipe in place or underneath the sink, the tool works great. Just ream the pipe or use a copper pipe cleaner before you do any soldering.What is the pipe cutting methods? ›
Pipe cutting, or pipe profiling, is a mechanized industrial process that removes material from pipe or tube to create a desired profile. Typical profiles include straight cuts, mitres, saddles and midsection holes.How do you do a straight cut with an oscillating tool? ›
To create a straight cut, a round or half-moon saw blade works best. You want to lightly press down on your tool creating a cut no more than 1/4 inch deep. Run your blade across the length of the cut multiple times with each pass making it a little deeper until you cut through your material.Why is it hard to cut cast iron? ›
More carbon makes the mix harder, more brittle, so less ductile. Cast iron contains MORE carbon than that rough upper limit of 2.1% for steel.Can you cut cast iron with a oxy fuel torch? ›
Oxy-fuel torches are normally used for cutting only ferrous metals and for the most part are not used for cutting cast iron, aluminum or stainless steel.Will a plasma cutter cut cast iron? ›
One of plasma's greatest advantages is its ability to cut non-ferrous metals such as aluminum, stainless steel and cast iron, materials that are becoming more common in many applications.Will a metal cutting disc cut cast iron? ›
The disc's long lasting durability maximizes cutting even in extreme applications such as rebar, angle iron, cast iron and steel bar.What is the easiest way to cut iron? ›
An angle grinder fitted with an abrasive metal-cutting disc works well to cut all kinds of metal, including bolts, angle iron, rebar and even sheet metal. But the discs wear down quickly, cut slowly and shrink in diameter as you use them. Instead, we recommend using a diamond blade that's rated to cut ferrous metal.
Do you soak cast iron in water? ›
Can I soak my cast iron pan? No! Soaking cast iron in water is a recipe for rust. If you need to remove sticky or stubborn stuck-on food, use a nylon scrubbing brush or a pan scraper and rinse under warm water.Can I cut cast iron pipe with a grinder? ›
Best Grinder Blade for Cast Iron
As I begin cutting with the angle grinder, it does a good job of cutting through the pipe. I then begin to move the grinder back and forth along the initial cut.
Cut Smarter: Use a Reciprocating Saw
Mount a metal-cutting blade in your reciprocating saw and you've got the ultimate power hacksaw for cutting bolts, rods, pipes and angle iron. A recip saw with a metalcutting blade also works great for remodeling demolition when there are nails and pipes to cut off.
The metal cutting bandsaw is ideal for projects of all sizes. It can cut up to six tubes simultaneously—which makes it one of the most efficient tool of this list. If you are cutting tubes daily, this tool is perfect for the job.Can you cut pipe with a reciprocating saw? ›
Reciprocating saws fitted with the correct metal cutting blade make easy work of sawing through bolts, rods, rebar, pipes, profiles, and nails in stud work. Reciprocating saws cut by the blade travelling in a backwards and forwards, push- pull movement.Will a Sawzall cut through metal? ›
With the right blade, your sawzall can cut through wood, nails, fiberglass, branches, plaster, masonry, and metals including aluminum, cast iron, steel, and even high-strength alloys.