Choosing and Using Hand and Power Saws
Sheet materials need firm clamping at a number of points while being sawed. The cut section should also be supported, so that it does not break off and leave a splintered edge.
Hand saws
There are two main types of hand saw – those with flexible blades for cutting wood to size and those with braced blades – usually having smaller teeth- for more accurate cutting.
Using a hand saw
Grip a hand saw with your index finger extended along the side of the handle, and push from the shoulder.
Because the saw teeth are set at an angle to the blade, to the right or left alternately, they make a channel wide enough for the blade to slide through without jamming.
If the teeth do not bite into the wood, they need sharpening. If the saw wanders to one side, the teeth need repositioning with a purpose made tool called a saw set.
Always mark a cutting line on the wood. Saw just on the waste wood side of the line; if you saw along the line itself, the work piece will be fractionally too small. If sawing a coated board – such as veneered or melamine chip board – score a deep cutting line on all four edges with a sharp knife held against a straight edge. Saw from the top, as the underside may chip slightly.
Flexible hand saws
The most common flexible saws are the cross cut, panel saw and ripsaw. A cross cut saw has its teeth sharpened at an angle of about 70 degrees on each edge, so they cut in both directions. Use the saw to cut across the grain of timber. It is about 640mm long and has six to eight teeth per 25mm. Use it at an angle of about 45 degrees to the wood. A panel saw is a smaller version – about 501mm long and with ten teeth per 25mm. Use it for sheet materials such as plywood.
Ripsaw
This has its teeth sharpened at right angles to the blade. It is about 650mm long with five teeth per 25mm. Use it to cut along the grain of the wood, working at a steep angle – about 60 degrees.
General purpose saw
A plastic handle which can be angled to suit the work in hand is common on this type. Its blade is designed to cut either wood or metal – or both together. Use this saw for cutting secondhand or scrap timber which could have hidden nails in it. Take great care if you use it to cut floorboards – it will cut through pipes and cables very easily.
Padsaw
Also called a keyhole or compass saw, this is uses for awkward interior curs such as keyholes or making a square cut out in plasterboard. Fit the blade with its teeth sloping forward; some padsaws take a range of blades including broken hacksaw blades. Drill a start hole in the waste part of the wood, then saw using short, gentle strokes.
Rigid hand saws
The tenon saw is the most widely used type. It has a steel or brass strip folded along the top edge to keep the blade rigid, and is usually 250mm long with 14 or more teeth per 25mm. A dovetail saw is a smaller version. These are the saws to use for cutting woodworking joints.
Coping saw
A bow shaped metal frame and handle is used to hold a thin, fine toothed blade which is secured by clamping. Keep the tension on the blade tight. The blade holders can be swiveled so the saw can cut in any direction. For normal work, have the cutting teeth facing forward so that you cut on the push stroke. For very thin materials, set the teeth backwards and cut on the pull stroke. To make an internal cut, first drill a hole through the wood. Thread the blade through, then connect it to the saw frame.
Fretsaw
The frame holding the fine toothed blade is deeply bowed, so that you can cut well into a thin piece of wood. The blade is secured at each end by a thumb screw. Clamp the wood flat, so that the area to be cut overhangs the bench. Cut with the handle below the work and with the teeth facing the handle. Use short, steady strokes.
Hacksaw
This cuts most metals and also plastic pipes. It has a bow frame and handle, into which blades are inserted with teeth pointing forwards. Some frames are adjustable to take different blade lengths. There is a range of tooth sizes and spacing; as a general rule use fine teeth for sawing thin sheet materials, and coarse teeth for soft materials like aluminum. There are junior and mini hacksaws for fine cutting, and for working in confined spaces.
Sheet saw
This is used to cut large sheets of metal, where a hacksaw cannot be used because the frame limit’s the length of cut. It resembles a rigid saw, but has a hacksaw blade attached to its cutting edge.
Log saw
This garden saw has a tough tubular steel frame to hold a steel blade. Sizes range from 610mm to 910mm. The teeth are designed to cut the wood and clear the sawdust. The blade cuts equally well on both push and pull strokes.
Pruning saw
A simple handle holds a curved blade which has teeth facing backwards, so you only cut on the pull or downward stroke.
Power saws
For safety, always plug a power saw into a plug in circuit breaker. Unplug the saw whenever you are not actually using it. Always use a sharp unbent blade and fit it the correct way round. Keep the cable well away from the blade.
Wear safety goggles to protect your eyes from fragments and sawdust. Make sure that the blade cannot damage anything underneath it.
Using power saws
Hold the saw back from the wood, press the trigger, and when the saw reaches full speed, start the cut. For a clean cut, set the cutting depth 3mm deeper than the wood.
Do not force the saw along – you will only slow down the blade, which needs to be at full speed to work best. When the cut is finished, allow the blade to stop before removing it from the wood.
Power saws cut from underneath or on the upstroke. Because of this, you should put coated boards face down for cutting; score the face with a sharp knife and draw a guide line on the reverse for following with the saw.
Circular saw
Although these are available as attachments to an electric drill, it is better to use a purpose made one, which is more powerful.
Use the saw for straight cuts in timber and board. However, it is limited by the maximum depth of cut – normally 48mm on a 150mm blade. Blades may be set to cut full or partial depth, or to cut at a given angle.
A selection of blades is available – for general sawing of timber and boards; for finer cutting across the grain of hardwood and softwood; for coarse cutting with the grain of the wood; for very fine cuts on all timber and board; for cutting abrasive materials like chipboard where the bonding material would quickly blunt an ordinary blade; for a cutting copper, lead and brass or other alloys; and for cutting masonry and ceramics.
Jigsaw
More versatile than a circular saw, a jigsaw will take a range of blades for cutting wood, plaster, metal, leather and rubber. The saw can have variable speed, a dust extractor, a swiveling head to cut curves and a pivoting and retractable sole plate.
Reciprocating saw
Also known as the power sabre saw, this relatively new tool is really a powered hand saw. It will cut a variety of materials, from thick tree branches to metal tubing. You will need both hands to hold it.
