How to Cut Cast Iron Pipe

Cast iron pipe was long the go-to material for plumbing. So, there’s a good chance that your plumbing pipes are made from cast iron pipe if you own an older home.

That’s why it’s so important to understand how to cut cast iron pipe if you’re about to tackle a DIY plumbing project.

Sure, the thought of cutting through such a strong yet brittle material might seem intimidating, but it’s actually very easy with just a little know-how and the right tools.

At the end of this guide, you’ll feel completely comfortable cutting cast iron pipe for your plumbing project.

What You’ll Need

There are a number of different ways how to cut cast iron pipe.

Here are the tools and materials you’ll need for the five most popular methods:

Method I: Hacksaw

  • Hacksaw
  • Replacement Blades

Method II: Cold Chisel

  • Cold Chisel
  • Ball Peen Hammer
  • Chalk

Method III: Snap Cutter

  • Snap Cutter

Method IV: Reciprocating Saw

  • Reciprocating Saw
  • Diamond Blade

Method V: Angle Grinder

  • Angle Grinder

Your best bet is to choose the method that utilizes tools you already own. That said, the methods that utilize power tools are typically much easier than those that utilize hand tools.  

Method I: Hacksaw

You might think that cutting through cast iron pipe with a hacksaw is the cheapest method.

Well, you’re sorely mistaken.

Although the actual hacksaw is perhaps the cheapest tool on this list, the hardness of the cast iron pipe will require you to go through multiple replacement blades.

For this reason, I don’t really recommend using a hacksaw as anything but a last resort. It’s also the slowest and most exerting method.

If you do choose to use a hacksaw, the job basically consists of sawing back and forth to cut through the entire pipe, replacing blades as needed.

Method II: Cold Chisel

Another handheld method to cut through a cast iron pipe is with a cold chisel and ball peen hammer.

Although this method actually makes the cut more easily, the downside is that it requires a lot of skill to perform successfully.

Because of the skill and experience required, the cold chisel method should only be used by those that already know how to use this hand tool.

Another downside is that you need plenty of space to operate. Not only do you need access to the entire pipe (including all of its sides), but you also need enough room to use the hammer.

If you do use the cold chisel method, start by drawing a cut line with chalk on the pipe. Use the cold chisel and ball peen hammer to make small cuts until the pipe breaks clean.

Method III: Snap Cutter

Yet another handheld method is to use a snap cutter.

Most home DIYers don’t own a snap cutter, but they’re easy and quite affordable to rent from a home improvement store.

A snap cutter is by far the most common method that plumbers use when working with cast iron pipes. It creates a clean cut with minimal effort.

You’ll notice that a snap cutter consists of a roller chain and a ratchet that actually performs the cut (or break).

Simply place the chain around the pipe and apply pressure on the ratchet handles. The chain will cut into the pipe until it eventually breaks into two. 

Method IV: Reciprocating Saw

Don’t fancy cutting through cast iron pipe with a hand tool? Or maybe you already have a reciprocating saw laying around.

In that case, a reciprocating saw is a great way to cut cast iron. The catch is that it requires a special diamond blade to do the job.

A reciprocating saw outfitted with a diamond blade cuts through cast iron pipe very quickly without much dulling. It’s also a relatively nimble tool capable of working its way into cramped locations. 

Like the other methods on this list, using a reciprocating saw to cut your cast iron pipes is relatively straightforward.

Simply mark the cut line with chalk, turn on the machine, and then slowly and gently work through the pipe until it breaks.

Method V: Angle Grinder

Another power tool that excels at cutting through cast iron pipe is an angle grinder.

In fact, it’s the classic power tool of choice for the job. It makes the cut quickly and easily without much strain on your part.

Make sure that your angle grinder is outfitted with a blade that’s designed to cut metal. A 4-inch diamond blade is probably your best bet.

Create a chalk line on the cut mark. Then use the angle grinder to slowly cut through the pipe until it breaks into two.

Anytime you’re using power tools, especially a potentially dangerous one like an angle grinder, it’s important to wear the proper safety equipment such as ear protection, eye protection, and sturdy work gloves.

Final Thoughts

There are a bunch of different ways how to cut cast iron pipe.

The one you choose should depend on the tools available to you, your power tool experience, and the scope of your project.

After reading our detailed guide above, you now have the information needed to use any of the five most popular methods to cut a cast iron pipe.

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