How do I saw a straight line by hand?

Sawing straight is almost entirely about how the cut is started and where your arm is, not about strength.

Safety

What you'll need

• A sharp saw with the right tooth count
• A bench hook or clamps
• A square and a sharp pencil

Step by step

1. Choose the right saw.Fine teeth for a clean cut in thin material, coarse for fast cutting through thick softwood. A tenon saw for joints, a panel saw for boards.
2. Mark the line all the way round.Square across the face and down both edges. It gives you a line to follow on the far side, which is where cuts usually wander.
3. Decide which side is waste.Mark it clearly. The saw kerf removes about 1 to 2mm, so cutting on the wrong side makes the piece short.
4. Support the work properly.A bench hook or clamps. Anything that moves as you saw makes a straight cut impossible, and it is the most common reason beginners struggle.
5. Start with backward strokes.Two or three light pulls to establish a kerf. Pushing on the first stroke makes the blade skip across the surface.
6. Use your knuckle as a guide.Thumb knuckle against the blade side, not the fingertip near the teeth. It steadies the blade until the kerf is established.
7. Cut at about 45 degrees.For general crosscutting. Shallower for a finer finish, steeper for speed. A very steep angle tears the fibres on the underside.
8. Line up shoulder, elbow and blade.Your arm should swing in the plane of the cut. Most wandering cuts are a body position problem rather than a technique problem.
9. Use the full length of the blade.Long steady strokes rather than short fast ones. Short strokes wear one part of the blade and cut slowly.
10. Let the saw's weight do the work.Pressing hard bends the blade and pushes the cut off line. Guide it rather than forcing it.
11. Watch the line, not the blade.Look slightly ahead of the cut. Watching the teeth means you correct after drifting rather than before.
12. Check both faces as you go.Pause and look at the underside. Correcting a drift early is easy; discovering it at the end is not.
13. Correct gently by twisting.A slight twist of the blade steers it back over several strokes. Forcing it sideways binds the saw and can kink the blade.
14. Support the offcut at the end.Hold it or have someone hold it. An unsupported offcut breaks away and splinters the last part of the cut.
15. Slow right down for the last few strokes.Light strokes prevent breakout on the far face.

Tips

• Start with backward strokes. Pushing on the first stroke is why saws jump.
• Line up your shoulder, elbow and the blade. Most crooked cuts are arm position, not skill.
• Mark the line on all four sides so you can see it from the underside too.

Common mistakes

• Pressing hard to cut faster — It bends the blade and pushes the cut off line, and in a fine saw it can kink the plate permanently. The saw's own weight is close to the right pressure.
• Cutting on the line rather than beside it — The kerf removes 1 to 2mm of material, so cutting down the centre of the line makes every piece undersized.

If it doesn't work

Questions people ask