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Cryogenics
Cryogenic heat treatment is increasingly being used in the production of cutting
tools; the change in micro structure achieved by the extreme cooling process
improves wear resistance and thus the service life of the all-important cutting
edge. The cryogenic process consists of soaking the finished component for
something like 20 hours in liquid nitrogen at a temperature of -195°C and
then re-tempering to toughen the material and restore its original fracture
resistance.
Not all materials respond equally well to cryogenic treatment, but the A2 alloy
steel used in the manufacture of Lie-Nielsen blades is particularly suitable
with the result that something like a doubling of the time between re-sharpenings
can be achieved.
Manganese Bronze
Although Lie Nielsen use ductile cast iron for most of their planes, they prefer
manganese bronze for some of their smaller tools. Manganese bronze is a very
hard, strong alloy which wears very well, unlike brass and softer bronzes. It
looks good, is heavier, does not rust, will not crack if dropped and has a warm
feel in the hand. Cast iron is used when the extra weight is not welcome.
Squareness of Plane Bodies
Lie-Nielsen make a point of grinding the sides of their plane bodies square to
the base (+0/-0.025mm), something that not all manufacturers do. This is particularly
important on planes such as rebaters and the No. 9 Mitre Plane, where squareness
between two planed surfaces is important to the final result
Stress Relieving
Stress relieving, the process of stabilising castings so that they do not distort
over time, can be achieved by leaving the castings out in the open for many,
many months to age. However, a quicker and more controlled method of achieving
the same end is to heat the castings up to a high temperature and then leave
them to cool slowly. This process is used by Lie-Nielsen to ensure that their
plane bodies are stable and do not distort subsequent to machining, particularly
necessary in the case of long-bodied planes.
Blades
It goes without saying that the blade is the most important part of a hand plane.
Lie- Nielsen blades are made from A2 steel and are both thicker and harder than
those from other manufacturers. The extra thickness gives a smooth, chatter-free
cut whilst the Rockwell 60-62 hardness gives longer service between re-sharpening
and thus, in the long term, a longer lasting blade. Careful heat treatment produces
a fine grain structure so that the blade will take a very fine edge. The final
step is a full surface grinding of the top, back and cutting edge, giving a smooth
flat surface requiring little or no honing before use.
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Improved
Chipbreaker Design
The chipbreaker serves two functions; firstly, it provides support for the blade
right up to the cutting edge to prevent chattering and secondly, it guides the
shavings away from the mouth of the plane to prevent jamming. Lie-Nielsen bench
planes feature an improved style of chipbreaker, 3.2mm( ")
thick with a 0.4mm(.015") lip ground at a 1° angle to provide the best
possible contact between the leading edge of the chipbreaker and the blade. If
you have an older Lie-Nielsen plane, you can upgrade it with an improved chipbreaker.
 Chipbreaker
upgrades - click for more information
Ductile Iron
Grey cast iron has long been the traditional material for plane bodies; it is
cheap and relatively strong but it does suffer from the problem of brittleness
which makes it vulnerable to cracking when dropped. Ductile iron, on the other
hand, with its greatly improved tensile strength and ductility, is a lot less
brittle and will withstand dropping from a considerable height without breaking.
Even the most expensive of tools do get dropped from time to time and it is good
to know that your valuable investment will withstand such maltreatment.
Tuning
Tradition has it that a new plane has to be 'tuned' prior to use; a lengthy process
which consists of checking and correcting the flatness of the sole, adjusting
the shape of the mouth by filing if necessary, flattening the back of the blade
and grinding and honing the cutting edge. The good news is that when you buy
a Lie-Nielsen plane all this has been done for you before it leaves the factory.
The sole, and sides where applicable, are ground to within 0.03mm(0.0015")
flat and square, the mouth is properly formed, all the contact areas are smoothed
off and the blade is honed ready for use. All this means that a Lie-Nielsen plane
is
truly 'ready-to-use' straight out of the box.
Keeping a keen edge
The sharpening of edge tools is a very complex subject, written about in enormous
detail over the years and abounding with all sorts of theories on the best methods
and materials needed to achieve the perfect cutting edge. All these theories
have their pros and cons and it is up to the individual to decide what is best
for them.
Perhaps the best sharpening advice of all is 'little and often'; if you keep
on top of the job with regular touch ups on a strop or a very fine waterstone
your tools will always perform at their best and you will avoid the need for
tedious re-grinds. Only if you chip the edge or let it get too blunt will you
need to resort to more drastic measures.
As already mentioned, Lie-Nielsen planes are delivered ready for use and should
not need any further attention before use, apart from maybe a light honing. |
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