If it's not already in your toolbox, it should be: a hacksaw. This classic tool is an indispensable ally when you need to cut metal, plastic, and other hard materials that most saws can't handle.
What Is a Hacksaw?
A hacksaw is a hand tool with a removable blade used for cutting metal and plastic. Due to the alignment of the teeth on the blade, the saw cuts on the forward, not the backward, stroke.
What a Hacksaw Is Used For
A hacksaw is mainly used for cutting thin metal such as aluminum, brass, steel, or copper. Hacksaws are also used for cutting plastics such as PVC, PEX, or ABS on pipes or on sheet goods made of PVC, polystyrene, and more.
A hacksaw should not be used for cutting wood or stone.
Parts of a Hacksaw
A hacksaw consists of two main parts: the metal frame with handle and the removable blade.
A hacksaw frame is C-shaped with a handle at one end. The hacksaw blade runs across the open end of the frame. Most hacksaw frames are 6, 10, or 12 inches in length.
A hacksaw blade is a thin band of metal ranging from 6 to 12 inches long. The blade mounts to the frame on pins. After it has dulled, a hacksaw blade cannot be sharpened. It must be disposed of and replaced with a new blade.
Once the blade is drawn tight in the frame, the thin metal gains enough strength to be used as a saw.
Hacksaw blades have between three and 32 teeth per inch (TPI). Most blades range from 18 to 32 TPI. Blades that have more teeth per inch are used for cutting finer materials.
A hacksaw is generally safe to use because the blade's teeth are soft to the touch. Like any other saw, though, pressure on the saw increases its cutting strength. Keep hands and the rest of your body away from the hacksaw blade when cutting.
Improperly tensioned hacksaw blades under pressure may break or can suddenly come apart from the hacksaw frame. Sharp metal, plastic, or the tool itself can cause harm. Make sure that the blade is well-tensioned and straight.
How to Use a Hacksaw
Mount Blade on Frame
With the frame's thumbscrew retracted, insert the blade into both of the frame's retaining pins. Tighten the thumbscrew clockwise until the blade is tight and does not wobble side-to-side. Use a rag to rub two or three drops of machine oil across the blade.
Clamp Work Material
Clamp the work material into a vise. Or, use clamps to hold the material to the work table.
Hold Hacksaw Correctly
Hold the hacksaw with one hand on the grip and the other hand at the far end of the frame.
Press forward on the saw an inch or two to create a starting notch in the material.
Saw the material by moving forward and back in full strokes. Press firmly down on the forward stroke, but not so much that you twist the blade. Ease up on the pressure for the backward stroke.
Tips for Using a Hacksaw
- Use the entire length of the blade when cutting.
- Make sure the blade is firmly tensioned.
- Press firmly on the forward stroke, not on the backward stroke.
- Add machine oil where appropriate to cool the blade and material.
When to Replace Your Hacksaw Blade
Hacksaw blades are meant to be replaced as needed. If you rarely use your hacksaw and it's used only for light work, it may need to be replaced once every six months or year.
It's usually time to replace the blade when you run your finger backward on the teeth and the coarseness feels the same as if running it forward. You'll also know when it's time to change the blade when you have to push hard on the saw to cut the material.
Deciding Which Kind of Hacksaw Blade to Use
Buy the right length of hacksaw blade for the frame.
When cutting aluminum, choose a blade with fewer teeth per inch, as aluminum shavings tend to clog up hacksaw blades.
Hacksaw blades with 18, 24, and 32 TPI are suitable for most applications.
When cutting ferrous materials (those containing iron), look for high-speed steel (HSS) or bi-metallic blades, as they tend to wear better.
Hacksaw vs. Oscillating Multitool
One alternative to a hacksaw is an oscillating multitool fitted with a blade rated for metal. While both tools can cut the same types of materials, they are typically used in different ways.
Slower cutting time
Cuts on forward stroke only
Easy to hold
Faster cutting time
Cuts both forward and backward
Difficult to hold
Electric (battery or corded)