- Jigsaw blades and their uses pt.1:
- History of Jigsaw and blades for metals
Pictures from AEG, permission to use from www.aeg-pt.fi
History of Jigsaw
- Jigsaw is basicly hand tools which don't use electricity. They originally used muscle power ! :)
The
electrical jigsaw was invented at Robert Bosch company at 1947 by one
of it's employee. Legend says this employee replaced the needle from
his wife's sewing machine with a saw blade. Since that this power-saw
had some difficulties to come to common markets since Scintilla
(nowadays Bosch) had supplied the German army during second world war.
That was the reason for allied powers to blacklist company during that
time. So from 1947 to 1964 the unit was marketed in the U.S. under the
name "Lesto". After that it was named "Bosch."
Some improvements during years
Bosch has sold approximately 20 million jigsaws and is the leading supplier of jigsaw blades in the world.
Jigsaw developments include the introduction of adjustable pendulum action in 1966, the Click system technology for tool-less jigsaw blade changing in 1989 (using a specially designed T-shank blade), and the in-line jigsaw, an all-purpose tool that reaches into tight spots and can be used as a power rasp for shaping wood or as a high-speed brush with available accessories.
You can see the cross-section image from an AEG-jigsaw and you
can start to understand how complicated it is to build it from scratch.
That's the reason to buy good guality no tool this complicated can be
any good if it is on sale or in lowest price!
- Sawing of metals, the basics
- When sawing metal it is highly important to NOT press the saw blade hard against the material being sawed. It will not make the sawing action quicker, it is more likely that you cause too much stress to the components and motor of your jigsaw. Use only small force to press the saw blade against the material being sawed.
-
There are two other things to consider when beginning to saw metals. You should select the most
appropriate
blade for your metal. You should also consider using of cutting oil of
some kind. This will keep the blade cooler and even sharper for longer.
But when using of cutting oil you will see that the metal particles
like to stick to your blade, it should not do any harm but might cause
extra mess. -
One thing in all jigsaw blades that differ is the distance
between two teeth. When selecting you're blade you should know what
kind of metal you're going to saw and how thick that material is. The
thinner material also requires blade with smaller teeth and smaller
distance between teeths. The correct sizing of teeth prevents even the
thinnest metal sheet from tearing. The general rule is that at least
three (3) teeth should be in contact with the metal at the same time.
When this is accomplished you should not see any tearing happening.
Blades for Aluminium
Blades for aluminum have usually bigger teeth which improves the removal of chips and smaler particles. Usually when you find that it is slow to saw aluminum, the thing that makes it slow is those aluminum chips which can stuck between the blade and the sawed material,
"choking" your blade. Using
of cutting oil might help with this. After using of cutting oil it is
likely that the chips will stick to the sides of your blade. Usually
blades for aluminum have so big teeth that they wont choke at all.
Blades for metal and rost free materials
Blades for harder metals have more smaler theets and thinner blades. But still the same principle works: the thicker the material the bigger the theets. But this time the hardnes of the metal should be considered allso. So for thick and hard metal needs smaler theets than as thick but softer metals. With these kind of metals you should always use cutting oil of somekind.
This blade has 0.7mm distace between teeths and length of an 55mm. AEG says that this
blade
is ideal for curved cuts and layered materials, rost free steel, metal
and PVC-plastic. I would allso say that this is ideal for very thin
metals (aprox. 1.4mm - 2.1mm) and even for thinner metal sheets. When
using thinner (below 1.4mm) metal sheets you should allso use somekind
wooden board behind and on top of the sheet to prevent tearing and
bending from happening.
This blade is very similar to the above one but it has bigger teeth and more recognisable
s-curve,
which you can see when looking straight at the saw teeth. So the
distance between teeth is 1.2mm and length the same 55mm. It has still
the same usage as the above except this blade is more efficient with
thicker (and softer) metals from 2.4mm to 3.6mm. I wouldn't use this
for sawing thin metal sheets since tearing is most likely to happen!
This blade has quite big theets and is very fast for softer materials. You can use this allso
with aluminum, but as always think the thickness of the material before using big theet
sawblade! Too big theets may even cause damage to your jigsaw! This saw
has 2.0mm distance between theets which makes the suitable material
thickness from 4mm to 6mm or even more. - Keypoints to remember:
- -Allways use cutting oil / liquid of some sort
-Ethanol is the best for aluminum, but can rust your drill press's "pole"
-When selecting sawblade be sure to select a sawblade with small enough theets
there should be 3 theets always touching the metal, therefor the right density of those
theeths are thickness/3
-Remember that too big theets and too thin material thickness may injury your jigsaw!
- This was just an short presentation of jigsaw blades for metal.
At the next part of this series we're going to see lots of different blades intended for wood.
-Sawing metals, basics
-Aluminum
-Other blades for metal
-Keypoints to remember
-PART 2: Blades for wood