Hacksaws are a staple in most toolboxes, and with good reason. These versatile hand-held saws can cut through a wide variety of materials with relative ease.
This article delves into hacksaws for metal cutting and the factors to consider when choosing a blade.
Can a Hacksaw Cut Metal?
Yes, a hacksaw can cut metal. This handy tool is used to cut bar stocks, thin plates, rebars, angle irons, etc. Generally, you will need a coarse blade for cutting soft metals and a fine pitch blade for tougher metals such as steel.
For best results, use an HSS or bi-metal saw blade with 18, 24, or 32 TPI blades.
See the hacksaw blade for metal cutting section for more details.
What Materials Can a Hacksaw Cut?
Hacksaws can cut a wide variety of metals, the most common being brass, aluminum, copper, and steel. They can also cut plastic materials, such as PVC, Perspex or plexiglass, ABS, polystyrene, etc. You can also use this saw to cut softer materials such as rubber, hardboard, wood, MDF, etc. with a low TPI blade.
Typically, you would use a hacksaw to cut pipes (both metal and plastic), bar stock (round and rectangular), or thin metal plates.
What Thickness of Metal Can a Hacksaw Cut?
Hacksaws can cut through various metal thicknesses, ranging from thin sheet metal to thick metal pipes.
There are two caveats here:
- hacksaw frame depth and
- material thickness.
Thin metal tends to deform when applying too much pressure. If you want to cut thin sheet metal using a hacksaw, ensure that the blade is sharp, and don’t apply too much pressure while cutting. Instead, work in slow, smooth strokes and let the saw do the work.
If you’re cutting thick metal, you’re limited to the dimensions of the saw frame. A hacksaw is made of a D-frame into which the blade is screwed. If this frame is smaller than the object you aim to cut, you’ll need a larger saw or a different tool.
Most standard hacksaw frames have a depth of 3-inches and are designed to work with 12″ long blades. If you measure the distance from the edge of the frame to the cutting edges of the blade the distance is 3 ¼ inches. Hence, in theory, a hacksaw can cut up to a depth of 3-inches before the workpiece starts touching on the frame.
In practice, though, you could cut 2 to 2 1/2 inches thickness from one side. You could reverse the piece and repeat the process to cut a maximum material thickness of 5-inches.
Hacksaws aren’t meant to cut large, solid blocks of metal. Instead, they’re better suited to cutting through smaller bar stock, pipes, and sheets. So, if you want to make a clean cut on a large, solid piece of metal, opt for a different tool, such as a metal cutting chop saw, power hacksaw or bandsaw. Hacksaws will do the trick when cutting through thick steel pipes, provided that the frame is larger than the pipe’s cross-section.
Can a Hacksaw Cut Metal Screws?
Yes, a hacksaw can cut through metal bolts and screws, provided that the blade is harder than the bolt in question. When cutting bolts, ensure that you match the blade to the application.
Screws and bolts typically have a hardness of 32-38 HRC (Rockwell Hardness Scale). Compare that to HSS (high-speed steel) with a hardness of 60-64 HRC and cobalt bi-metal blades with a hardness of 66-68 HRC. As you can see, the blades are far harder on the Rockwell scale than the bolts and will, therefore, quickly complete the task.
If you’re unsure which type of bolt or screw you’re working with, opt for a blade material further up on the Rockwell hardness scale. Also, ensure that the blade is sharp since a dull blade will cause untold frustration and pose a safety risk if it snaps mid-cut.
Can a Mini Hacksaw Cut Metal?
A junior hacksaw (6-inch blade) or a mini hacksaw can be used for cutting metal. However, the process is slower compared to a full-size hacksaw since the stroke length on a junior hacksaw is much smaller and you cannot exert pressure on the mini saw.
Any excess force will result in blade breakage.
Hacksaw Blade for Metal
Hacksaw blades are removable and typically range between 6 to 12 inches (15 – 30cm) in length. Depending on the application, the teeth on these blades range between 3 and 32 TPI (teeth per inch). The way these teeth are designed allows them to cut on the forward stroke instead of the reverse, and they can’t be sharpened once dulled. This means that you should replace dulled hacksaw blades, unfortunately.
What Type of Hacksaw Blade Cuts Metal?
The 3 most commonly available hacksaw blades are high carbon steel, HSS, and bi-metal blades. Generally, an 18TPI (Teeth Per Inch) high speed steel (HSS) is best for cutting softer metals such as aluminum and brass while a 24TPI HSS or bi-metal blade works best on steel.
High Carbon Steel
High carbon steel blades contain between 0.6% and 1.4% carbon by weight. These blades are strong and hard, but they are also more brittle than their HSS and bi-metallic counterparts. High carbon steel can get dull quicker at high temperature and are usually not recommended for cutting steel. They’re typically used for soft metals and plastics.
High-Speed Steel
High-speed steel (HSS) is tough and abrasion-resistant, owing to the 8% cobalt content. HSS blades retain their cutting edge for longer, resulting in longer tool life. This is the most common metal used to manufacture hacksaw blades.
Bi-Metal Blades
Bi-metallic blades are equipped with high-speed teeth and will easily cut through most metals. This includes hard metals, such as steel. These premium quality blades tend to be more expensive than their HSS counterparts.
These blades are made from two dissimilar metals. They typically have a steel spring backing and HSS (high-speed steel) edge material welded onto the teeth tips. That means these blades have hardened cutting teeth yet a flexible body that is less prone to breakage.
TPI: What is TPI on a Hacksaw Blade?
TPI refers to teeth per inch, indicating how densely the hacksaw’s teeth are arranged. A higher TPI value allows for a finer cut on harder material, such as metal. Fine materials also require a higher TPI. Conversely, a lower TPI is better suited to soft material, like wood (we have a separate article on hacksaws for wood cutting).
Typically, a hacksaw would have 18 – 32 TPI, which works for most common tasks. TPI values outside this range are meant for specialty applications.
What is the Best Blade for Cutting Metal?
Different metals require different hacksaw blades. Here are some guidelines to help you choose the correct blade:
- Aluminum shavings easily clog hacksaw blades. When working with this delicate metal, opt for fewer teeth per inch on the blade since this will minimize the clogging.
- General applications usually work well with 18, 24, or 32 TPI blades.
- Ferrous metal (any metal that contains iron) typically works best with high-speed steel (HSS) or bi-metallic blades since they offer better wear.
Here is a guide to the TPI suited to each application:
| Teeth Per Inch | Recommended Uses |
| 10 – 14 TPI | To cut softer materials such as plastic, aluminum |
| 18 TPI (Coarse) | General-purpose blade. Cuts mild steel, rebar, angle iron, etc. |
| 24 TPI (Medium) | Works best for cutting steel bar stock. |
| 32 TPI (Fine) | Best for tough tool steels, hollow and thin sections such as galvanized pipes, electric conduit, or EMT (Electric Metallic Tube) |
How to Cut Metal With a Hacksaw?
The hacksaw blade is fixed on a frame that has a nut (usually in the front) to adjust the tension of the blade. You will perform the cutting by moving the blade forward and backward in which the forward stroke is usually the cutting stroke.
Cutting with a hacksaw is a straightforward process. However, there are a few important things you should remember.
Here is how you should use a hacksaw.
- Step-1: Mark the cutting line considering the kerf (thickness of the blade).
- Step-2: Install the blade on the frame with cutting teeth pointing forward. Adjust the blade tension to the correct level.
- Step-3: Clamp the workpiece securely on a vise or using clamps. Do not attempt to hold the metal workpiece in hand when cutting. This is not only an unsafe work practice, but will also force you to cut with one hand which is less effective.
- Step-4: Use a triangular file to make small notch at the cut line. This is to guide the hacksaw blade.
- Step-5: Place the blade in the notch and start moving the blade forward and backwards with your right hand holding the handle and the left hand at the front of the frame.
- Step-6: The hacksaw cuts in the forward stroke (push) and the pull stroke is idle. So, you should apply pressure towards the workpiece only during the push stroke and pull it back without any downward force.
- Step-7: Use the full length of the blade.
A mistake that novice users often make is to use only the center portion of the blade. By doing so, you are not only under utilizing the blade capacity, but also risk the blade getting caught in the kerf and breaking it.
How Do You Make a Straight Cut in Metal Using a Hacksaw?
Hacksaws are relatively easy to work with, but it is not easy to cut straight. There are some tricks to the trade that will help you make straight clean cuts.
Here are some pointers:
- Secure the workpiece in a vice or similar sturdy grip.
- Place the workpiece in the vice with the cutline as close to the vice as possible. This prevents wobbling and excessive vibration.
- Ensure that the blade is firmly tensioned.
- Hold the hacksaw firmly with both hands while standing in a comfortable position. This helps you balance your body correctly while cutting, assisting in a clean cut.
- Ensure that you use the entire blade length in one smooth stroke. Always make long, even strokes.
- Apply pressure on the forward stroke, not the backward one. Remember that the teeth cut on the forward stroke.
- Apply drops of cutting oil as needed to cool the workpiece and the blade.
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