Jigsaws offer the ability to make curved and straight cuts in a range of materials including wood, metal and plastic but it has to be said that, if you have much straight cutting to do, use a circular saw rather than a jig saw.
Jig saws are not really designed for straight cuts due to the fact that even over a small distance the blade has a tendency to bend and give more of a beveled cut as opposed to a dead square cut. Its much better to stick to curves or intricate work with them.
However, if you are careful, take your time, hold the base (or sole plate) flat on the item you are working with and don’t force it then it is possible to create a nice straight and square cut.
Jigsaw’s themselves, as mentioned above, really come to life when you need to form curves or other intricate shapes in a given material.
As I’m sure most that own a jigsaw would agree, it’s not uncommon for these tools to sit idol and unused for ages and then all of a sudden two or three jobs on the run will require its use.
Although this may seem like a waste of money if you’re only using once in a blue moon, when you do need it there isn’t really any other tool that won’t involve a huge amount of extra work that you can use.
If you are considering buying one or need to cut a detailed shape in a given object then read on, we will tell you all about these handy tools and exactly how to use them.
What to Look for When Buying a Jigsaw
Buying a jigsaw is not the same as buying a good jigsaw! Jigsaws are very versatile tools but the wrong one can make life really hard. If ever there was a case for spending as much money on a tool as you can, then a good jigsaw is where it should be spent.
Blade Locks and Attachments
The first thing to look at is the blade and how it is fixed in to the tool itself. With cheaper jigsaws the blade is held in by a clamp which is tightened by either a screwdriver or an allen key.
Do not buy a jigsaw like this. The threads on the screw allow sideways movement, sideways movement in the blade means it is impossible from the off to get a straight cut even when using a guide.
Also, in most cases, the screw will come loose while you are cutting, not only making this situation worse but also allowing the blade to either drop out, most likely vibrate and then usually snap off.
Always buy a jigsaw with a blade lock and release system, these are much more secure and hold the blade firmly in place.
The Base or Sole Plate
Its also important that the sole plate (or shoe as it is known in the US) on your jigsaw is rock solid.
The sole plate is designed to be set at different angles and just like the blade holder, this movement can be exaggerated over time leading to poor control over the blade.
If the tool you are looking at has the ability to tilt the sole plate to make angled or beveled cuts, make sure once it’s moved and locked into position it doesn’t move, even a tiny amount!
One other thing to look for in terms of the sole plate is that you can see the blade clearly and easily. This is essential as you have to be bale to see where the blade is cutting and whether you are following your cutting marks accurately.
The sole plates of some jigsaws are joined at the front and although this is okay, you only get to see a small section of your cutting lines or marks. On the whole it is a lot easier if you can see as much of your cutting line as possible.
Reciprocal Cutting or Pendulum Cutting
Cheaper jigsaws use a reciprocal cutting action for the blade. This means that the blade just goes up and down.
Better jigsaws have a pendulum or orbital motion set into the motor which, depending on the setting you are using, allows the blade to move backwards and forwards at an angle as well as up and down while you are cutting.
What this means is that you get a much more aggressive and therefore faster cut. This also provides a further advantage in that at the same time, by moving the teeth away from the material after each cutting stroke, it allows any debris to fall clear of the teeth.
This stops the saw from binding on the material and burning rather than cutting through it, meaning that the saw itself cuts much more efficiently and the cut is a lot cleaner and more accurate.
How Powerful Should my Jigsaw be?
In essence, a jigsaw needs to be powerful to maintain a decent cut!
A variable speed control (as seen below) is essential if you are planning to use your saw on a variety of different materials as the difference between cutting timber as opposed to perspex needs to be about 1000 strokes per minute. If you try and cut perspex at the same speed as timber, it just melts.
For most DIY jobs a jigsaw of about 600W will do the job, where as the professionals will use at least a 720W tool.
Different Parts of a Jigsaw
As you may have guessed from the above information, for a fairly simple tool that just cuts, there are quite a few different elements and features that you need to be aware of to ensure that the tool not only cuts a given material but does it cleanly and with accuracy.
To this end we will now give you full run down on the features that most saws will have:
Blade and Blade Clamp
As you may have guessed, the blade in a jigsaw is the part that does the cutting.
It extends downwards from the blade clamp, the the base of the sole plate and as the sole plate rests on the item you are cutting, the blade moves up and down and cuts its way through.
If you look at a blade closely you will be able to see that the teeth are angled upwards so they actually do their cutting on the upstroke (as the blade is moving upwards). It is possible to get blades that cut on the down stroke (reverse cut blades), but most work upwards.
If you would like to know more about the blades and the different types available, please read on below.
For the blade to do it’s cutting it must be fixed firmly to the drive gears and motor of the saw itself and to achieve this. it must be clamped. This is where the blade clamp comes in.
As we have discussed, there are two types of clamp; the blade lock system and the screw clamp.
With the blade lock, a spring loaded catch can be engaged and disengaged to fit and remove the blade. The notches on a blade lock blade are held internally by the catch firmly and will not give until the catch itself is released
The second type of clamp is the screw-type clamp. The blade is inserted in to a slot and then (normally) two screws are used to clamp the blade in place. As we have discussed, this is okay but it does have a tendency to come loose.
Blade Roller Guide
Between the sole plate and the blade clamp is the roller guide. Once the blade is inserted, it then sits on the guide and this helps to hold the blade in place and support it while it’s cutting away.
The roller guide itself normally features a slight concave recess that bevels down from the edges to its centre. The blade fits securely in this grove and in turn it also helps to hold the blade square against the item you are working on, preventing it from bending and ensuring that the teeth are kept square to the edge of the object you are cutting.
The sole plate (or shoe/baseplate as it can also be called) is the base of the saw itself and this is the parts that sits squarely on the item you are working on.
The sole plate ensures that the blade is kept at 90° to your material and also keeps the teeth straight and upright so that they cut in their most efficient position.
With slightly higher spec saws, the angle of the sole plate can be adjusted to allow the user to cut a bevel cut. Depending on the make or manufacturer this may be a screw adjustment or a twist lock (similar to a screw, but allows loosening and tightening by hand).
One of the main features to look for in a good quality jigsaw is a decent, solid and well manufactured sole plate, that should be constructed of, at minimum, steel or aluminium and also allow the user to easily see and follow any cutting lines.
Power Switch and Speed Control, Power Cord and Variable Speed Control
The power switch, power cord and speed control provide the saws motor with electricity and then allow this to be controlled to determine how fast the saw operates.
The power cord as you would expect is only present on saws that are main powered. It’s important to make sure your saw has a decent length power cord (at least 1.5m) as this will help during operation.
The power switch does what you would expect – it turns the saw on and off. On pretty much every saw, it is located just below the handle and allows the user to easily turn it on and off when gripping the handle.
On some saws, this can also act as a speed control, the more it is pulled, the faster the saw runs, as it is slackened off, the saw slows down.
Where the power switch allows the saw to run faster the tighter it is gripped, the speed control helps to limit the saws top speed.
Normally the dial is labeled 1-10 (or a similar scale) with 1 being the slowest setting and 10 being the fastest.
Tis is a highly useful feature if you are planning on using your saw to cut a variety of different materials as some need to be cut at slower speeds e.g. plastic and perspex (at high speeds the friction can cause it to melt).
Pendulum or orbital Control
Pendulum or orbital action is not always available on every jigsaw, but it is a very valuable asset in your cutting arsenal.
When activated, during cutting, the blade moves forwards and backwards as well as up and down. This increases the cutting ability of the saw a great deal, making the cut much more aggressive.
The control lever itself usually has up to 5 different settings, with each setting determining how far forwards the blade moves on each stroke.
As we have also stated, the act of the blade moving backwards also clears any debris away, putting less strain on the saw as the blade doesn’t get jammed or binds.
What Different Blades are There
Blades are also very important. Cheap blades go blunt very quickly.
A blunt blade has to work much harder to cut which puts a tremendous strain on the motor of your jigsaw and will eventually wear it out much quicker than it should do.
It also makes you try to push the jigsaw through the work which may damage the blade housing and scorch the timber, so you may save a few quid on buying cheaper blades but it will cost you in the long run in terms of a worn out saw and also a finished work piece that may not be as good as it could have been!
When it comes to blades, using the right blade for the job is also very important.
Although using a metal blade to cut a piece of timber will work, the cut may be a lot more course than it should be and it may also splinter, potentially damaging the overall finish.
There are blades made specifically for cutting the following materials:
- Plastic, perspex, fibreglass
- Hard and soft woods and timbers
- Metal – including aluminium and steel
- Masonry, plaster
- Glass and ceramics
- Thick and heavy fabrics such as leather and the similar
Another thing to be aware of is the length of the blade. The blade itself should be around an inch or so longer than the thickness of the item you are cutting (to prevent it catching).
Generally, blades that are longer in length tend to be a bit thicker. This is to help stop them bending quite so easily.
Due to their thickness, longer blades are not that suited to cutting delicate or sharp curves or shapes, this type of work should be left to the shorter blades as these tend to be a bit thinner which makes them easier to maneuver.
The number of teeth that feature on the blade is also a key consideration. The TPI (or teeth per square inch) states, as you might have guessed, how many teeth there are on the blade per square inch.
- The more teeth there are on the blade, the harder the material it will cut
- Blades with a lower TPI are mainly for cutting softer materials
- A blade with a higher TPI will generally make a much smoother cut
- Blades with a lower TPI usually make a rougher cut
We haven’t yet discussed the teeth of the blade in any great detail. If you look at a selection of blades closely you will notice that the teeth are slightly different shapes, sizes, angles etc….
In pretty much all cases, the teeth on the blade are either ground or milled. Milled teeth are generally not as sharp as ground teeth and due to this are more aggressive when cutting and due to this cut a fair amount faster.
Ground teeth are cut with a much finer edge making them much sharper. Due to this they give a much finer and accurate cut, ideally suited to softer items.
Here follows the different types of blades available and what they should be used for:
Softwood and Hardwood Blades
For the best chance of getting a decent cut when cutting either softwood or hardwood timber the following blade type should be used:
- Bi-metal or high carbon steel blade
- Reverse, side or taper shaped teeth
Plastic Cutting Blades
Plastics and acrylics are tricky to cut as at high temperatures and levels of friction they melt and distort, so with this in mind and with the aim of getting the best cut, they need to be cut at lower speeds.
In general a fine blade with ground teeth should be used, with at least 13 teeth per inch, or even a tungsten carbide blade. Set the saw to a slow cut using the speed control dial and take your time.
Sometimes applying masking tape over your cutting line can help prevent chipping as this can easily happen.
Steel and Aluminium Blades
Although aluminium is a softer metal that steel, in pretty much all cases that same blade can be used to cut either. With this in mind, a high speed steel or bi-metal blade should be used, with either a wavy or tapered tooth layout.
Ceramic Tiles, Stone and Masonry Blades
When cutting ceramic tiles or other masonry items, this does require a specialist blade, in this case, a tungsten carbide coated blade.
Unlike the traditional blades listed above, instead of teeth, these blades are coated in tungsten carbide, which to the eye, looks very much like grit.
If you tried to use a blade to cut a ceramic tile, chances are due to it’s quite brittle nature, it will shatter and splinter everywhere completely ruining it, but by using tungsten carbide, this kind of wears it’s way through the object as opposed to chopping it and avoid any splintering.
What Different Blade Fittings are There
As we have already discussed above, there are essentially two different types of blade fixing and attachment; a blade lock system or a screw and clamp.
As we have suggested, you should always go for a tool with a blade lock system (sometimes called T-shank blades) as this will hold the blade in place much more securely than the screw-type clamp (sometimes called U-shank blades) ever will, although when new, the screw clamp will work but as the tool gets older, this will wear and you will find yourself stopping to tighten the screw every few minutes.
So that you can easily identify which type of blade is for which type of system, here follows and image of each blade and what it should be used for:
How to Use a Jigsaw
Mark out Cutting Line on Your Work
The very first step, before you even touch your jigsaw, is to accurately mark out any cutting lines on your work so that you know exactly where you need to cut.
Using a pencil or decent marker pen, measure, mark and draw your cutting lines. Take note also of where you draw your lines.
For example if you measure and mark points and then join them with a line, is the line to the left of the marks, to the right or over the top of them. This is important as if you mark cutting lines over the top of your measurement marks and you then cut along that line, the object will then be too small as you should have cut to the left (or right depending) of the line, leaving it in place.
Additionally, make sure your cutting marks are clear and easy to see.
Place Your Work on a Solid, Flat Surface and Clamp it up
The last thing you want when trying to cut a straight line or a set of intricate curves is for your work to be moving and sliding all over the place or be balanced on a surface that’s isn’t totally flat and smooth, so that any cut lines fold in on themselves due to pressure from the weight of the saw above and trap the blade.
In any of these situations the chance is that burning or splintering will occur, damaging the item and the overall finish.
With this in mind, you work should be placed on a totally flat surface and clamped up so that it cannot move. A workbench or Workmate are ideal for this. If you don’t have your own work bench, find out how to build one here.
One thing to also bear in mind is that the blade runs quite a way down past the sole plate, so anything below it and the item you are cutting will also get cut! This is easy to forget and can end in disaster, especially if you are using your nice dining table as a bench and you accidentally chop through it!
Set up the Saw and Position it for Cutting
Using the information above, select the correct blade to the material you are working with and insert it in to the saw. Make sure that it is securely fixed in place and does not move. Plug your jigsaw in to a mains socket (skip this part of your saw is cordless) and make sure that you have plenty of slack on your cable so that it doesn’t catch on anything.
For the purposes of this project we are going to assume that your cutting line starts right at the edge of the object you are working on. In the event that your cutting needs to take place in the middle you will need to get the blade through the item to start cutting.
To do this, drill a 10mm or slightly larger (enough to get the blade through) hole in the waste section you are cutting out and then you can cut your way up to the start of a cut line. Just make sure you are drilling into the piece you’re going to disguard!
Position the front tip of the sole plate on the edge of your item, leaving roughly a 10mm gap between the start of your cut line and the blade. Gently pull on power trigger/switch to start the saw and then slowly slide it up to the start of your line, letting the blade touch and start the cut.
Now it’s just a case of applying gentle, forward pressure to the saw and making sure you are following your cut line accurately.
Never force a jigsaw to go anywhere, they are hard enough to control accurately at the best of times but if you try to push the blade any faster than it wants to cut, you will spoil the work.
If you are wanting to cut a curve, as you are pushing the saw forwards, gradually turn it in the direction of the curve as you are moving forwards. This can be a bit tricky to master to begin with so it’s well worth practicing on an old piece of timber before you attempt it on your finished article.
As mentioned above, the thinner the blade, the easier and sharper a turn it will make.
Don’t apply too much twisting pressure to the blade, although most are more than capable of performing this task, trying to twist it on the spot to make a 90° cut is asking a little too much.
With the above in mind, some curves are a little too sharp and intricate for a jigsaw to cope with. If this is the case then staged cuts are the way to go. By this we mean cut a series of lines through any waste sections (if there are any) up to meet your cutting line and then cut along your cut line and remove them.
As you are working on your item you may find that you need to move it to ensure that you are cutting in the easiest and least awkward positions. If you need to move it then by all means move it, there’s no sense in struggling, just make sure you clamp everything up tight again after you’ve moved.
One point to note when cutting acrylic, perspex or other plastics is to keep the protective film on then while you cut. This will help to protect the remaining surface from scratches and other damage.
Tidying up Your Cuts
With your cuts now made and your finished article ready, it’s time for a tidy up.
If you’ve been working with timber then it’s time to get the sand paper out. Depending on the type of timber will depend on what paper you should use. For rough cut timber, use a slightly courser paper e.g. 120 grit but for smoothed and planed timber go for something a little finer such as 320, 400 grit etc….
Work your way around any cut edges, smoothing off as you go until all done.
If you have been cutting acrylic or perspex, the only real way to get your edges as perfect as possible is to use wet and dry sandpaper. Get yourself a small bowl of water, wet the sandpaper suitably and then get to work.
Make sure you stop and check your progress often as you don’t want to sand off too much and also make sure that you wet your paper regularly.
For tidying up metal, the best and really only tool to use is a file. Files come is a range of grades (measurement of how course they are) but it’s best to start with quite a fine grade. There is a method to using a file correctly and to find out more about this, see our using a hand file project here.
Hopefully after reading through the above, you should be well voiced in how to use a jigsaw and select the correct blade for the material you are working with, but if you would like to know a little more, then check out the video below.
All project content written and produced by Mike Edwards