Description from Japan Wood worker :
Our Brush Hook Nobori Kama is great for removal of brush that is too
heavy for a weed cutter and too light for an axe. Swung like an axe,
the brush hook's long 14 inch hardwood handle and heavy, hand forged
laminated high carbon steel head give it a powerful cut. Cut with a
slicing rather than a hacking motion and pull back on the handle at the
end of the swing to utilize the 9 inch curved blade. This is a sharp
tool and you should always maintain a firm grip on the handle. Comes
razor sharp with a sheath for the blade.
The Brush Hook from Japan has a much thinner and more acute edge
profile than other varitions of the same tool, a trend common in general
with Japanese knives and edged tools.
The case is simple vinyl, care needs to be taken to avoid hitting
the snaps with the edge.
460 grams
0.210" thick blade
blade is 1.9" wide (at its widest)
center of mass is 6" in front of the handle
multi-faceted grind
More specifics on the grind, there is a primary flat grind about 3/8" wide at
6.5(5) degrees, it transitions into a convex bevel which is 8.5 (5) degrees
at the shoulder and tapers to a very fine edge at 12.0 (5) degrees per side.
Initial impressions :
grip is roundish, concerns about rotation/security
light but with a huge amount of heft
very thin edge, high cutting ability but durability concerns
simple vinyl case
This should make an excellent light to medium brush cutting tool.
The primary grind is very acute and
tapers to a very fine edge so the cutting ability and ease of
sharpening will be very high. However the same geometry would likely
pose durability concerns on heavier work. This is definitely a
precision cutting tool.
There were a few isues with the tool however :
the blade, including the edge is covered in a lacquer
the handle is very rough, has machining marks
the wood is extremely dry, a bit of light rasping cracked it near
the blade cutout
the blade cutout is very sharp, abrasive to grip
These issues were easily fixed by :
cleaning the edge with a 4000 grit waterstone
rasping the handle and coating in boiled linseed oil
Comparing the rough carving ability to a
#1260 Mora the performance of the brush hook
in terms of ability to remove wood is actually slightly higher.
The picture at the right shows the results of one hundred
light cuts with each knife (10-20 lbs of force).
Due to the thinner primary grind the brush hook will tend
to naturally want to ride deeper into the wood
note how
thick some of the shavings are in comparison to the Mora pile
The pile from the brush hook weighs 110 grams and the Mora only
90 grams showing a 20% advantage.
The brush hook performs slightly better as it
has a thinner profile. While the very edge on the brush hook
has a slightly heavier angle
it quickly thins out due to the multi-faceted grind
and gets thinner than the Mora behind the edge.
The brush hook is also comfortable to hold
(with the above as noted modifications to the handle)
as it is neutral balanced when held right in front of the blade.
With a very forward grip it is actually comfortable to hold and the cutting
performance is actually very high due to the very thin edge profile.
For example it not only out cuts the Junglas
on such work but it even cuts with less force than the
#1260 Mora, again same as on the wood
because of the primary grind thinning back the edge. The only downsides are :
Comparing the rough carving ability to a
#1260 Mora the performance of the brush hook
in terms of ability to remove wood is actually slightly higher.
The picture at the right shows the results of one hundred
light cuts with each knife (10-20 lbs of force).
The materials cut were :