How to Cut Cast Iron Pipe with an Angle Grinder

how to cut cast iron pipe with grinder

Cast iron pipe was once heavily utilized for providing exceptionally strong and long-lasting pipework for drains and sewers. Although the pipe has since fallen out of favor due to heavy rust accumulation, a cast iron pipe is still used for a variety of reasons, and nothing can cut cast iron pipe quite like an angle grinder.

How to Cut Cast Iron Pipe with an Angle Grinder: To cut a cast iron pipe with an angle grinder, use a diamond blade to cut around the pipe. Once equipped, be sure the pipe is held in place by a vice or clamps and begin making circular cuts until you have penetrated through the entire cast iron pipe. From there, continue cutting until completed.

There are some things to keep in mind when it comes to cutting a cast iron pipe with an angle grinder; both for the grinder itself and the particulars of cast iron in general. Read on to discover what steps to take to make effective cast iron cuts as well as some related questions for angle grinder cutting.

Steps for Cutting a Pipe with an Angle Grinder

Cutting cast iron pipe or, any pipe in general with an angle grinder is almost guaranteed. This is because grinders can cut through virtually anything as long as you have the proper blade attached based on the material you are cutting.

To cut the pipe with a grinder, follow the following steps:

  • Choose a quality cutting disc. A diamond blade is truly the best kind of blade to use since the force will be greater when working with powerful metal piping such as a cast iron pipe.
  • Mark your cuts. It is essential to mark the section of the pipe you will be cutting to ensure that the cuts are accurate and properly aligned.
  • Always use safety gear. PPE (personal protection equipment) should include eye goggles, face shields, gloves, apron, and optional respiratory protection equipment.
  • Set up your work station. You will need to place the pipe on a well-suited workbench and it is best to use a bench vice to hold appropriately hold the pipe in place to avoid slippage or jagged cuts.
  • Begin cutting. Move the grinding tool along the pipe to weaken the pipe and effectively cut through the material.
  • Have patience. Depending on the type of pipe you are cutting, you may need to make several movements of the grinding tool around the circular pattern of the pipe to finish the cut. If the pipe is proving to be too heavy, you can use a saw or a chisel to finish off any loose edges that are not wanting to break off.

Keep in mind that the process can change drastically depending on where the pipe is and how difficult it may be for cutting as opposed to a loose pipe that can be placed on a workbench. For a situation like this, using a grinding tool may not be the best method.

The great thing about a diamond blade is that this blade can fit easily onto a reciprocating saw, which is probably a lot easier to maneuver in enclosed spaces than a powerful grinding tool that can emit an incredible amount of sparks.

Can I Use a Grinder to Cut Cast Iron Pipe?

Cast iron pipe can be a bit more problematic than something as easily cut as PCP pipe. Cast iron pipe can be incredibly heavy, therefore, gripping the pipe in place with a bench vice or alternatively, clamps if the pipe is set in place, is highly recommended to avoid problems with handling the pipe.

Follow these steps when using a grinding tool as a way to cut cast iron pipe:

  • Be mindful of the weight of the cast iron pipe. For a pipe that is vertical and in place, using a grinding tool can be dangerous if the weight of the cast iron closes down on the cut. Clamps are a great way to hold the cast iron pipe in place to prevent this from occurring.
  • If possible, always consider using a reciprocating saw. Grinders will certainly get the job done, but the difficulties (and time) that come with this method are not always worth it. A reciprocating saw can be used for cutting cast iron pipe so much more effectively since the circular shape of a cutting blade for a grinding tool is not as threatened by the weight of the cast iron pipe.

The best way to cut a cast iron pipe with a grinding tool is to make sure the pipe is not vertically in place or under a house in a tight and small space. The possibility of the weight of the cast iron pipe falling on the grinding blade is too great and the sparks emitted from the grinding tool can be problematic as well.

The choice of cutting wheel is also crucial if you decide to cut a cast iron pipe with a grinding tool. The cutting wheel needs to definitely be made for cutting metal and a carbide disc or diamond disc is the best for the job.

As we will discover in the next section, there are better tools to use for cutting cast iron pipe.

What Is the Best Way to Cut Cast Iron Pipe?

To cut a cast iron pipe, you need a tool that can make quick slices to prevent the cast iron pipe from collapsing. There is perhaps no better tool for this job that a reciprocating saw.

Follow these steps when using a reciprocating saw as a way to cut cast iron pipe:

  • Choose a good variety of blades to cut through the pipe. Heavy Duty Metal Cutting Reciprocating Saw Blades by Janchi come in a pack of 5 blades and are perfect for cutting cast iron pipe. These blades can effectively improve the strength, hardness, and heat resistance of the reciprocating saw, in addition to making the blades resist high temperatures on heavy metal cutting.
  • Spray the cast iron pipe with WD-40 to lubricate the pipe for cuts. Lubrication will work wonders for loosening up the cast iron pipe, which is prone to collecting rust in a short amount of time.
  • Make your marks for the reciprocating saw. Pencil in a line around the pipe to guide the saw around the pipe in a straight line. When you cut cast iron, the saw blades will likely be unusable afterward, therefore, it is essential to make the perfect cut with the saw in one go.

Following these steps will ensure that you are able to make cutting cast iron with a saw a much easier process than using a grinding tool. Also, be mindful of water or mud if the pipe is submerged or near water, this will certainly make using a grinding tool a near impossibility.

Frequently Asked Questions

What Are the Best Types of Blades for Cutting Metal?

The best type of grinding tool blades is always going to be the blade that can be used for multiple techniques without the need to constantly stop and change to a new type of blade. This blade type would definitely be a cutting blade, which is crucial when it comes time to cut cast iron.

A cutting blade allows you to cut through a range of materials and also use the edge of the blade for some quick grinding touch up work after the cutting process is complete. By using the top center-most portion of the cutting blade, you can effectively grind and alternately go back to cutting to save a lot of time in what can be a long and laborious process.

You will want to choose blades that are guaranteed to withstand intense cutting pressure with the co-grinding capabilities that can be utilized with a cutting disc. Additionally, to cut cast iron, a saw would be best, but metal blades are non-negotiable if you decide to use a grinding tool.

The Metal and Stainless Steel Cut Off Wheels by Black Hawk are some of the best cutting blades available due to the durability and precision put into the wheels to cut a variety of strong metals.

You can buy these quality blades as a 25-pack and the 1/16 inch thickness is guaranteed to provide razor-sharp cutting with an adequate thickness for grinding that is both durable and long-lasting.

Can You Use an Angle Grinder to Cut Wood?

An angle grinder will cut through almost anything, so yes you can definitely use an angle grinder to cut wood. The problem is, wood is like paper to an angle grinder. The blade is simply far too sharp and powerful to cut material without many possible problems occurring, therefore, a saw is the best method to slice wood.

Let’s like at a few potential problems in more detail:

  • Using an angle grinder to cut wood can result in kickback. Angle grinders are made to cut through metal, concrete, and other thick materials. When you use an angle grinder to cut wood, there is very little resistance since the blade is far too powerful for wood.
  • Wood is not thick enough to hold the grinder in place. When you are making cuts, the blade will run all over the place because the density of the material (wood) is not strong enough to control the blade based on your movements.
  • The angle grinder will run off course. Since wood is so thin to a grinder, you will have a powerful device running at up to 15,000 RPM veering of course, and potentially cutting you because there is no resistance to focus the blade on.

So while you can rest assured that an angle grinder will cut through wood, this is not recommended due to the power of the tool for such a lightweight material.

With that said, there are some types of blades that are designed to cut wood with an angle grinder.

Grinder Wood Carving Disc GRAFF Speedcutter 4-1/2-Inch, TCT Circular Saw Blade for Angle Grinder - Woodcarving Saw Blade 7/8" Arbor, Sculpting, Shaping and Cutting Wheel with 3 Teeth (115 mm)
  • Multifunction circular saw blade 4 ½ Inch for angle grinder is an ideal solution for wood carvings, sculpting and shaping. This woodworking tool has 3 tungsten carbide teeth and antikickback design, and it is safer than 6 teeth wood carving disc. This is one of the most universal wood carving tools and angle grinder attachments. ✷This wood grinding wheel was certified by MPA Hannover.✷
  • This grinding disc 4 ½ Inch has unique tungsten carbide semi-circular tooth shape and because of this can replace wood carving tools set. It can be used as grinder shaping disc, sculpting wheel and cutting wheel and also circular saw blade.
  • Angle grinder wood cutting wheel GRAFF Speedcutter does not overheat even after continuous work. This grinder disc ensures safe work because the carving blade creates reasonable radial resistance value at high rotation speed rates 13200 RPM. This angle grinder wood saw disc (wood carving chain disk) has a special design in which the disc body has feed stop. Working with our woodcarving disc is safer than with wood carving chainsaw blades and simple saw blades.
  • GRAFF Speedcutter is a multipurpose wood cutter (wood carving wheel). This circular saw blade is intended for carving not only wood but also plywood, laminated flooring, parquet (hardwood), plasterboard, MDF (hardboard), chipboard, etc.
  • This angle grinder cutting wheel provides smooth grinding and carving. One more advantage is the right grinder blade diameter – 4 ½ Inch and 5 Inch allowing easy multipurpose work on a variety of materials.

The Grinder Wood Carving Disc by Graff is one such blade that is specifically used for angle grinders and woodcutting. This woodworking blade has 3 tungsten carbide teeth and an anti-kickback design, and it is generally safer than a 6-teeth wood carving disc.

This type of blade is one of the most universal wood carving tools and angle grinder attachments. Since grinders spin at up to 15,000 RPMs, this blade is pivoted with three teeth to adequately work against the incredible resistance that arises when an angle grinder cuts into material that is thinner than what high RPMs are made for.


Cast iron is a heavy and dense material that is best-suited to be worked on with a saw since a saw can slice through the material quicker. You can certainly use a grinding tool, but always be mindful of the potential that the pipe may collapse due to its weight, which could cause major problems with a circular disc.

Ben Jones

When it comes to selecting the right tool for the job there are some important factors that you have to consider. I hope by sharing some of my knowledge I'll be able to educate you on a range of grinders so you can get the job done.

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