How to Cut a Cast Iron Pipe With a Sawzall


If you want the best way to cut through a cast iron pipe, look no further than the Sawzall or reciprocating saw, as some like to call it. The Sawzall is the most versatile and efficient bladed tool you need in your toolbox when working with cast iron.

Despite being an ideal instrument to cut cast iron, using the Sawzall can be challenging for beginners. Even if it does not require much setup, it does present some hazards, like many other electric tools. 

The secret to successfully cutting a cast iron pipe without kickback or unexpected binding is to set up the reciprocating saw properly and handle it with the utmost care. To help you do this, we have put together four safe and easy steps to guide your use of the Sawzall on cast iron.

Step #1: Set Up the Sawzall

Best Cordless Reciprocating Saw in 2022 – Reviews & Buyers Guide
Image by Makita File:Makita JR3070CT Reciprocating Saw via Wikimedia Commons

One of the most important components of the Sawzall is the blade. The blade in a Sawzall moves back and forth while cutting through materials; therefore, it is crucial that you find the right blade for the job. Materials have different densities; hence you should have more than one blade to switch them up.

You must get a metal-cutting blade or diamond reciprocating saw blade for cast iron pipes. When you buy the blade from your local hardware store, read the product description to see if they have listed cast iron as one of the materials it can cut through. The blade must be about three inches longer than the cast iron pipe thickness.

Before installing the blade, make sure you did not plug the Sawzall into an electric outlet. If you are using a battery-operated saw, ensure it is switched off and remove the battery pack from the tool. To insert the blade, locate the blade clamp (chuck) on the Sawzall. This is the metal piece on the end of the saw that holds the blade in place to prevent it from wiggling. If you don’t know where it is, look for it with the help of the tool’s user manual.

Once you have located the blade clamp, unlock it by pressing down the button or lever. You must keep holding it down while simultaneously inserting the blade into the slot. Let go of the button or lever only once you have fully inserted the blade. To ensure that the blade is firmly inserted and won’t fall out, give it a gentle tug and adjust the shoe (metal piece around the base of the blade.)

Step #2: Set up the Pipe

step #2 set up the pipe
Photo by Bernard Hermant on Unsplash

Cast iron is very tough and heavy; thus, it is harder to cut than standard steel. If you are working with a lone pipe piece, start by clamping it to your worktable. Then, leave the cut-out part hanging off the table. Use a clamp specifically made for pipes to avoid rolling or slipping. If you are working on an installed pipe, ensure it is steady and won’t move while you’re cutting through.

Before cutting, you have to lubricate the pipe with a metal cutting liquid or lubricant. Cutting the pipe without lubrication will cause friction and potentially destroy the blade. Lubricate the pipe after clamping it down so that it doesn’t slip through. WD-40 and 3-in-one oil will work on cast iron but if you can’t find it at your local hardware store, ask the store clerk for alternatives.

Marking a visible line on the cast iron pipe with measuring tape and a permanent marker will help. The marked line will show you where to place the blade and how to align the tool. The mark will make it easier to cut through the pipe cleanly and prevent an accident.

Step #3: Learn How to Hold the Sawzall and Wear Protective Gear

Best Cordless Reciprocating Saw in 2022 – Reviews & Buyers Guide
Image by Mark Hunter on Flickr

Don’t forget to adhere to the basic safety rules. Wear safety glasses that adequately cover your eyes, suitable quality gloves, earplugs, and a dust mask while working with the Sawzall. The dust that comes off when cutting cast iron is dangerous and can cause serious health complications.

Hold the Sawzall firmly when you’re cutting through the pipe. You do so by supporting the tool’s weight by grabbing the area just behind the blade clamp with your hand. With your free hand, grab the end of the tool that has the trigger. Remember to keep your finger off the trigger until you are ready to cut through the pipe.

Avoid wearing loose-fitting clothing as these could get caught in the blade. Keep an appropriate distance from the tool when you are operating it. Be mindful of where the blade is pointing to prevent any accidental injuries.

Step #4: Cut Through the Cast Iron Pipe

cast iron pipe ready for cutting
Image by Xtrodinary on Pixabay

The angle at which you hold the Sawzall will make cutting through much more effortless. So, angle the saw slightly downwards and position the blade at the end of the marked line. Plug your Sawzall in or insert the batteries and switch it on. The saw shoe must sit tightly against the pipe to prevent kicking back while you are cutting.

Lightly pull the trigger on the saw with the index finger on your dominant hand, and from a safe distance, observe whether the blade moves back and forth. Please wait for the tool to reach its optimum speed and guide the blade through the pipe. While you are cutting, keep the shoe of the saw firm against the pipe and change the angles to lessen the surface area so that the blade cuts faster. Do not pull the edge out of the pipe under any circumstances, as this could result in kickback.

Use your whole body weight to apply pressure rather than just your upper body. If you’re solely using your arms, you will tire fast, especially when cutting through a thick and heavy material like cast iron. Fatigue is likely to lead to reduced pressure on the Sawzall and consequently result in you accidentally lifting the blade.

When you temporarily stop the blade, you must let go of the trigger, as this prevents the blade from going back and forth. When you finish cutting and you want to switch the tool off completely, take your finger off the trigger and switch it off. You do so by either unplugging the cord or clicking the “Off” button and removing the battery pack.

Frequently Asked Questions

1. How do I know when my sawzall is damaged?

Whenever something feels or sounds off when using it, there is probably some damage. This could be an unusual sound or a change in how it cuts through materials. If you notice anything out of the ordinary, it’s best to turn it off and take it to a repair shop to get it checked out.

Also, regularly check the saw for visible damage, like cuts in the cord or dents on the surface. If you have dropped it and you are concerned it might have affected how the saw operates, get it checked out before trying to use it.

2. What is the difference between cast iron and steel?

Cast iron and steel are both alloys composed primarily of iron atoms. The difference between the two metals lies in their carbon content. Cast iron has 1% to 1.5% more carbon in it than steel, and steel can contain no more than 2% of carbon. Cast iron is usually cheaper than steel because it has lower material costs and a quicker production process.

3. What kind of cuts can be made with a reciprocating saw?

The cuts you can make with the reciprocating saw depend majorly on the blade you use. Sawzalls can cut through metals, wood, plastic, fiberglass, stucco, masonry, and drywall. You can cut almost anything if you insert a blade suited for the material. You only have to ensure that what you want to cut is not too large for the saw. If it is too large, it’s probably better to find an alternative tool built to handle the material.

Final Thoughts

A Sawzall is a handy and versatile tool; using it is easy with the right blade and technique. When cutting through cast iron, a saw diamond blade or metal-cutting blade is going to do the trick. Remember to stay safe while using the tool; this means wearing suitable gear and staying aware of the environment you are working in. If you have any doubts about the parts mentioned, use the tool’s user manual to make sure you have identified the correct component. 

Regular maintenance will keep your Sawzall functioning at its best, especially when cutting through metal. Lubricate the blades regularly, store the saw safely and lubricate the cast iron pipe before you cut through it. If you were uncertain about using the reciprocating saw to cut a cast iron pipe, these steps would help you safely do so. 

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