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Hand Saws, Hacksaws and Blades: Choosing the Right Tooth Count
A hand saw is chosen by tooth count and tooth shape, not by the length of the blade. Two saws the same size will behave completely differently because one has 7 teeth per inch for rough timber and the other has 32 for a metal tube. This guide explains what the numbers mean, which saw covers which material, and how to keep a blade cutting straight.
Teeth per inch and what it controls
Tooth count sets the trade-off between speed and finish.
- Few, large teeth. Cut fast, remove a lot of material, and leave a rough edge. Right for rough timber, pruning and demolition.
- Many, small teeth. Cut slowly and leave a clean edge. Right for trim, laminate, plastic and metal tube.
- Set. The sideways offset of the teeth creates the kerf and clears the sawdust. A blade with no set will bind in the cut, which is what makes a saw wander.
- Tooth shape. Rip teeth cut along the grain, crosscut teeth sever fibres across the grain, and a hacksaw’s fine teeth cut on both the push and the return in some patterns.
Matching the saw to the material
| Material | Tool | Typical tooth count |
|---|---|---|
| Rough timber and framing | Hand saw, long blade | 7 to 9 TPI |
| Trim, plywood and laminate | Hand saw, fine blade | 12 to 16 TPI |
| Metal tube, angle and bar | Hacksaw frame | 18 to 32 TPI |
| PVC, conduit and plastic | Hacksaw or fine hand saw | 18 to 24 TPI |
Hand saws for wood
Hand saws in 270, 300 and 350 mm lengths cover framing and general cutting, where a long blade with coarse teeth keeps the cut straight over distance. A second range of hand saws with different blade lengths suits finer work and trimming, where a shorter, stiffer blade is easier to control. Blade length should match the width of the material: a short saw in a wide board will wander, and a long saw in a small section is harder to steer.
Hacksaws for metal and plastic
Hacksaw frames in aluminium alloy take standard blades and let you tension them properly, which is what stops a blade bending in the cut. A simple fixed hacksaw frame is the cheap way into metal cutting, and for occasional work it is entirely adequate. The blade is the consumable, not the frame: a dull blade is what makes a hacksaw wander, and pressing harder only wears the teeth faster.
Blades and the saws they fit
Hand saw blades in 300 and 500 mm lengths replace the cutting edge without replacing the tool, which is what you want if the frame or the handle is still good. A wider range of blade lengths and thicknesses covers panel saws and specialist frames, and the thickness matters as much as the length, because a thin blade cuts faster and wanders more. Where the cut is in a confined space, shorter saws around 250 mm reach where a full-length blade will not, and general blades in longer lengths cover the rest of the range.
How to cut straight and keep it that way
Most wandering cuts come from technique rather than the tool. Start the cut with two or three backward strokes to establish a kerf, then use long, light strokes that use the whole blade, because short strokes wear the middle teeth and leave the ends sharp. Let the saw do the work and do not lean on it. Support the material close to the cut on both sides so it cannot pinch the blade, and if the cut closes up, wedge it open. For metal, reduce the pressure and keep the strokes slow: heat is what destroys hacksaw teeth, and a blade that is hot to touch is being ruined.
Frames, tension and blade fitting
A hacksaw only cuts straight if the blade is tight. Tension the blade until it rings when you pluck it, and fit it with the teeth pointing away from the handle so the cut happens on the forward stroke. A loose blade bends in the cut, which is what produces a curved cut in a straight line of metal, and a bent blade never recovers its shape. Most frames adjust for blade length, and the common sizes are 250 mm and 300 mm, so check which blade your frame takes before buying a pack. A frame that will not hold tension is a consumable too.
Saw horses, supports and safe cutting
Support is what makes a cut predictable. Rest the material on a saw horse or a bench hook close to the cut line on both sides, so the piece cannot drop and pinch the blade as it separates. Where the material is round, such as pipe or conduit, clamp it or use a vise, because a round section will roll as the teeth bite. Keep the off hand clear of the blade path rather than holding the piece near the cut, and where a cut needs to be exact, score a line around the whole section first so you can see the blade drifting while there is still time to correct it.
Frequently asked questions
How many teeth per inch should a hand saw have?
Seven to nine for rough and framing timber, twelve to sixteen for trim and sheet goods, and eighteen or more for metal and plastic.
Why does my hacksaw wander?
A dull blade, too much pressure, or a blade that is not tensioned properly in the frame. Replace the blade and tension it so it rings when plucked.
Can I cut metal with a wood saw?
Not usefully. Wood saws have coarse, set teeth that will skip over metal and blunt almost immediately. Use a hacksaw blade for metal.
Which way should a hacksaw blade face?
Teeth pointing forward, away from the handle, so the saw cuts on the forward stroke. The blade is stamped with an arrow showing the cutting direction.
How do I stop a cut binding?
Support the material on both sides of the cut, use a blade with enough set to clear the dust, and wedge the kerf open if the material pinches. Binding is usually a support problem, not a blade problem.
Where to start
Browse the full Hand Tools range, or the wider Hand Tools category if you also need cutting tools, files or measuring equipment. Tell us the material and the finish you need, and we will point you at the blade and tooth count that fit.
