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Jigsaw Cutting Technique: Pendulum Action and Clean Edges
A jigsaw is the most misused saw in the workshop. It will cut a curve in a worktop, a hole in a cabinet back and a shape in sheet metal, and it does all three with the same motor and the same blade holder, which is why the blade fitted for the last job is usually wrong for this one. Most ragged cuts, bent blades and burnt edges come down to three things: tooth pitch, pendulum action and how hard the saw is pushed forward. This guide covers the technique and the blades in this range.
Match the blade to the material
| Blade | Material | Note |
|---|---|---|
| HCS, coarse pitch | Timber, board, plastic | Flexible, fast, dies quickly on metal |
| HSS or bi-metal | Steel, aluminium, metal sheet | Hardened teeth survive the heat of cutting metal |
| Fine pitch | Sheet, laminate, thin tube | Keeps teeth in contact with thin material |
| Extra-long blade | Thick sections, deep cuts | Reaches where a standard blade is buried |
Wood and plastic
A woodworking jigsaw blade set in HCS carbon steel is where most jigsaw work starts. High carbon steel teeth are sharp and cheap, and for timber, board and plastic that is all you need; the same blade will not survive long in metal because the teeth soften as they heat. Choose the pitch by thickness, so a coarse blade clears the dust out of a thick section and a fine one keeps teeth in the cut on thin board. Cut from the good face and let the saw do the work, because pushing a jigsaw only makes the blade bend and the cut wander away from the line.
Metal and alloy
An extra-long T318A jigsaw blade for metal in alloy steel is the blade for a long cut through steel, aluminium or a mixed assembly. The hardened teeth hold their edge when the material gets hot, and the extra length means the blade is not bottoming out in a thick section where a standard blade would be buried in the cut with nowhere for the chips to go. On metal, slow the saw down, reduce or switch off the pendulum action, and use a lubricant, because the failure mode here is heat rather than force.
Fine work and tight curves
A 75 mm T244D jigsaw blade in HCS for wood and plastic is the blade for detail. A short blade is stiffer than a long one, so it follows a tight radius without bowing, and a fine pitch leaves a cleaner edge on a visible face. Use it for cut-outs, for radiused corners and for any cut where the line has to be followed accurately rather than covered by a trim. If the cut matters, cut slightly outside the line and finish with a file or a flush trim bit, because a jigsaw blade deflects under load no matter how careful the operator is.
Pendulum action: the setting nobody uses properly
Pendulum or orbital action pushes the blade forward as it rises, so the teeth take a bigger bite and clear the dust faster. It is the single fastest way to speed up a wood cut, and the single fastest way to produce a ragged edge. Use the highest orbital setting for rough cutting of thick timber, drop it to nothing for laminate, veneered board, plastic or metal. Orbital action also increases blade deflection, so on a curve the blade leans and the bottom of the cut runs off the line even when the top of the cut looks perfect.
Getting a clean edge
- Support both sides. Clamp the work so the offcut cannot drop and pinch the blade. A closing cut is what bends a blade.
- Score the line. On a visible face, run a knife along the cut line first, or lay tape over it. Both stop the surface splintering before the teeth get there.
- Start on the waste side. Cut just outside the line and leave the last millimetre to a file, and the finished edge is straight regardless of blade wander.
- Steady feed. Push at a speed you can hear: a saw that is labouring is a saw that is bending its blade.
- Let the blade stop. Do not lift the saw while the blade is still moving, because the last centimetre is where most edges get wrecked.
- One blade per job. A blade that has cut metal will never cut a clean edge in timber again. Keep the two sets apart.
Cutting a hole without a pilot drill
An internal cut-out starts with a plunge or a pilot hole. If the blade can plunge cut, tilt the saw and bring it up to speed before the teeth touch the work, then straighten it slowly; if the material is hard or the finish is visible, drill a hole at a corner of the cut-out instead and thread the blade through it. Either way, start from a stable position with the front shoe flat on the work, because the shoe is what sets the cut angle. A plunge made with the saw tilted and the shoe off the work will bend the blade before the first tooth has cut anything.
Frequently asked questions
Which jigsaw blade cuts both wood and metal?
None properly. HCS blades are for wood and plastic, and bi-metal or HSS blades are for metal. A blade used outside its material either dulls immediately or burns its way through.
What is pendulum action for?
Speed on soft material. It makes the blade take a bigger bite, so it suits thick timber and should be switched off for laminate, plastic and metal.
Why does my cut wander at the bottom?
Blade deflection. Use a shorter or stiffer blade, reduce the feed, switch off pendulum action, and cut slightly outside the line so the error can be filed away.
How do I stop the top surface splintering?
Score along the cut line with a knife or lay masking tape over it, and cut with the good face down where the blade cuts into the material rather than out of it.
Why does the blade keep breaking?
Almost always a pinching cut, a bent blade from a previous cut, or twisting the saw while it is running. Clamp the work so the offcut cannot close, and keep the saw flat.
Where to start
Browse the full Jigsaw Blades range, or the wider Cutting & Measuring Tools category if you also need band saw blades, drill bits, squares or gauges. Tell us the material, the thickness and how clean the edge has to be, and we will point you at the pitch and blade length that suit the cut.
