The new generation of power saws - jigsaws, reciprocating saws, circular and mitre saws - are more accurate and make lighter work of woodworking tasks than their predecessors. This guide will help you choose the best tool for the job.
Types of Saw
There are three main types of power saw: jigsaws, reciprocating saws and circular saws. Take a look at the table to find out how well they cut various materials.
|Material||Type of cut||Jigsaw||Reciprocating saw||Circular saw|
|Wood, MDF & Plywood||Straight line cut||Good||Fair||Excellent|
|Cross cut (wood)||Fair||Fair||Good|
|Metal||Straight line cut||Good||Good||Not possible|
|Plastic||Straight line cut||Good||Good||Fair|
|Aluminium||Straight line cut||Good||Good||Not recommended|
|Masonry||All cuts||Not possible||Possible with a special blade||Not possible|
Key features to look for when choosing a saw:
• Length of stroke - This is the distance the saw blade travels up and down. On a jigsaw, for example, a 20mm stroke means the blade will move 20mm down and 20mm up to complete one stroke. The longer the stroke length of the saw, the greater the number of teeth that come into contact with the material in each stroke cycle.
• Strokes per minute - The amount of times the blade travels down then up in one minute. The higher the number of strokes per minute, the higher the number of cuts and therefore the faster and more efficient the machine.
• No load speed - The amount of times the blade travels up then down (or the number of complete revolutions for a circular saw) each minute. 'No load' refers to the motor speed when the saw isn't actually cutting (this usually decreases when it is).
• Power input - The amount of watts that the motor draws (or needs) from the electricity supply. Usually the greater the watts, the more powerful the motor will be.
• Maximum cutting capabilities - The thickest material that the saw can cut, as recommended by the manufacturer.
• Blade bore diameter (for Circular Saws) - This is the diameter of the hole in the middle of the blade. This hole (called the 'blade bore') varies from one saw to another, and it's very important that you use the correct size blades for your machine.
• Keyless blade change – For quick and easy blade change.
• Variable speed – Different speeds are required for different applications so being able to vary speed improves the versatility of the tool.
• Pendulum action - The normal action of a jigsaw blade is a straight reciprocating action, up and down. On pendulum action the blade also travels back and forth. By adjusting the amount of movement the aggression of the cut can be increased to make the blade cut faster, although the finish may not be as fine if cut at speed.
• Dust extraction – Collects dust for a cleaner work environment.
• Universal blade clamp – There are two different types of jigsaw blade fitment – T shank and U shank. Some jigsaws will only accept one type or the other but universal blade clamp models accept both T and U shank blades.
• Bevelling shoe – A moveable shoe plate which allows you to cut at angles.
Highly portable, and now available cordlessly, jigsaws cut through metal, wood, plastics, aluminium, laminates and ceramic tiles - as long as you fit the right blades for the job. Because of their narrow blade, they're particularly ideal for cutting curves and awkward shapes. That makes them very useful if you're cutting shelves, laminate flooring, kitchen worktops, skirting board and shapes to make items like toys.
A jigsaw has a slim reciprocating blade that cuts on the upstroke as you feed it into the edge of the wood or board (except for a laminate cutting blade, which cuts on the downstroke). If you do little more than the occasional sawing job, a single-speed jigsaw with an input power of 350-400 watts is ideal. Depending on the size of blade fitted, it'll cut wood up to 50mm-55mm thick - and a model with an adjustable soleplate will allow you to make bevelled cuts at angles of up to 45 degrees.
Spend a little more, and you could own a jigsaw with a range of additional features - like more power and a faster, deeper cutting performance. You can also expect things like variable speed control, pendulum action and an anti-splinter device for smoother, chip-free cutting (essential if you're cutting faced boards and laminated worktops). Cordless models are an ideal choice if you plan to use your saw regularly, or do not have access to a power supply in your workshop.
There are wood-cutting jigsaw blades for coarse, medium and fine cutting - the closer the teeth, the finer the cut. The same blades will also cut plastic. Blades for metal have much finer teeth and should also be used for cutting wood that contains nails or screws.
Special blades are available for cutting ceramics, glass-reinforced plastics (GRP) and laminates. Laminate blades cut only on the downstroke, allowing you to work with laminated materials the right way up without damaging the surface. The toothed section of the blade typically ranges from 50mm-105mm in length.
Reciprocating saws are designed for heavier-duty use than jigsaws, which makes them ideal for rough cutting when you need more power and less accuracy (such as demolition work).
They can cut a wide range of materials including metals, wood, man-made boards, plastic and even tree branches. So if you're cutting fence posts and decking; or removing old windows, stud partitioning, metalwork, or wood that's embedded with nails, this is the type of saw to choose.
How they work
Reciprocating saws are used with both hands, and their design makes it easier to cut overhead or vertically.
They work with an oscillating motion, with the blade going up and down. So for every back stroke, the blade angles downward into the cut slightly; and for every push (or forward stroke) it angles upward slightly. This helps you cut through materials (particularly wood) much faster. It does also makes a rougher cut than a straight back-and-forth cutting motion - but as reciprocating saws aren't normally used as precision tools, the finish of the cut shouldn't be an issue.
Changing the speed
Modern reciprocating saws usually come with variable-speed motors. All you do is press the trigger a bit harder to increase the speed at which the blade oscillates backwards and forwards. This gives you plenty of control - which comes in particularly handy when you're making wide curved cuts (for example, when you're moving from the side of a window cut-out to the sill on the bottom).
The disc-shaped blade of a circular saw makes professional-quality straight cuts in wood, plywood, MDF and kitchen worktops. It can be used freehand, guided by a parallel guide fence, or it can be mounted in a saw table with the blade projecting upwards through a guarded slot.
Cutting with a rotating action, circular saws are good for converting large pieces of wood and board to smaller sizes. Therefore, they come in particularly handy when you need to cut sheets of plywood, MDF doors and shelves, laminate flooring, kitchen worktops and decking. The varying models have blades of different diameters. The larger the blade, the thicker the material you can cut with it.
Look for helpful features such adjustable cutting depth, sight liner and adjustable fence guide. A vacuum cleaner attachment or dust collection bag will keep your work area clean and tidy.
For more complex jobs, a Mitre Saw can be used to make clean and precise cross, mitre and bevel cuts in hardwoods and softwoods, plastic, alloys and nonferrous metals. Additional features may include a laser guide for cutting accuracy, extension wings for larger materials, and dust extraction for cleaner operation.
For some tasks, a compound mitre saw or sliding mitre saw might be most appropriate. A Compound Mitre Saw allows the angle of the cutting blade to be changed to cut a ‘bevel’ i.e. an angled cut. A Sliding Mitre Saw allows the cutting blade to be moved up and down the workface, to make cuts that are deeper than the blade.
Choosing saw blades
When choosing a blade for a circular saw, you need to take three things into account:
- The correct blade diameter for your saw
- The right bore size (the diameter of the hole in the centre) - this may be 12.7, 16, 20 or 30mm
- The tooth size and number to suit the job
A blade with a few large flat teeth will give a fast, coarse cut, while a blade with a larger number of alternately offset teeth gives a medium or fine cut. Lots of small, flat, trapezoid-shaped teeth will give you the cleanest cut. All these blades have tungsten carbide-tipped teeth for long life.
More powerful saws take larger 180mm blades, and will cut deeper and faster.
Types of saw blade
Specialised circular saw blades are used to cut different materials: Choose the right blade for the best finish.
- Pointed tooth blade - suitable for cross-cutting solid timber, giving a reasonable finish
- Fine tooth blade - for fine cuts in chipboard and laminated board
- Ripsaw blade - rips through softwood, hardwood and man-made boards, leaving a rough-edged finish
- Chisel tooth blade - universal blade for soft and hard wood
- Carbide-tipped universal blade - top quality blade, cutting with a fine finish through all materials, including laminates