Choosing
the proper steel is a must in order to pass the ABS
JS test. I highly recommend 5160. Don't be fooled
by it
only
having 60% carbon. With proper heat treating it will
easily pass all phases of the test. I will take you
through step
by step, explaining the manner in which I would produce
a blade to pass the ABS Journeyman Smith test with
5160 steel.
FORGING: Either
1 ¼” or 1 ½” X ¼”
is the best size to start with for a test blade. Begin
forging with the highest heats you intend to use. Then
progressively reduce the heats throughout the forging
process. Pay close attention, and do not let yourself
be distracted from the forge! This is where most people
let their mind wonder and without realizing it, let
the blade overheat, which causes the grain to grow dramatically.
The reducing heats are intended to refine grain structure
as you go through the forging process. Ensure you leave
extra “meat” at the edge as “sacrificial” material
that will be ground away after the heat treat process.
Remember that you may use either a full or
hidden tang blade for the JS test, but for safety sake,
I recommend forging a full tang unless you feel supremely
confident that you can make a hidden tang that will
pass the bend test.
NORMALIZING: This
is a critical step in a high performance blade. Once
forging to shape is complete, and using a magnet to
determine critical temp, heat the blade to just critical,
and allow it to COMPLETELY cool in still air. This has
the effect of relaxing all the internal stresses that
have been built up during the forging process, and will
eliminate 90% of warpage problems. Multiple cycles are
of great benefit, and should be experimented with to
achieve optimum results in your shop.
ANNEALING: Once the
blade has completely cooled, it is time to anneal. Bring
the blade to a little past non-magnetic, and place in
a slow cooling media. I recommend vermiculite. Sand
is not a good insulator, and ashes draw moisture, which
can result in hard spots (something you certainly DO
NOT want at this point). I usually do my annealing in
the evening, and allow the blade to cool overnight.
Routinely it takes a test blade sized piece of steel
6-10 hours to fully cool in vermiculite. This step reduces
grain size within the steel, and may be accomplished
multiple times for added benefit. Like normalizing,
multiple annealing cycles are of added benefit to both
5160 and 52100.
ROUGH GRINDING: This
is simply where the blade is profiled and refined
prior
to the heat treatment. Distal tapers can be refined
or added at this point. Ensure you leave enough extra
material in the edge so as not to overheat it during
hardening. I recommend about the thickness of a nickel.
I choose to call this extra material “sacrificial”,
as it acts like a protective shroud to what will
be
the working edge of the blade. After rough grinding
is complete, ensure you go over the entire blade
with
at least a 120 grit to eliminate the possibility of
stress risers that may be caused by large scratches
that are left from the course grit belts.
HARDENING: Keep
in mind that we are talking about 5160 steel. I recommend
edge quenching ONLY on a blade that will be used
for
something as important as the ABS JS test. If you don’t
already have one, make a “limiter plate”
for your quench tank. This is nothing more than a ¼”
to 3/8” thick piece of aluminum that is choked
full of 3/8” holes. At each corner drill and tap
a ¼” X 20 hole and use carriage bolts
with the heads facing the bottom of the quench tank,
and
screwed into the holes at each corner of the plate.
This will allow you to raise and lower the quench depth
to fit any blade. Once the limiter plate is set to
the
proper depth (about 1/3 of the blades width), pre-heat
the quenching oil (I use vet grade mineral oil, and
like to quench in the 130-160F range. Be careful here;
DO NOT quench when the oil is 180F or higher. At this
temp the oil will not cool the steel fast enough to
achieve full hardness and your blade will not pass
the
chopping portion of the ABS JS test.
Using approx. a #3 tip on an Oxy/Acty torch, and with
a SOFT flame (a flame that does not roar, but has a
very mild hiss.), start heating the ricasso area near
the edge, and as soon as it starts to turn color, then
work the blade back and forth until it is just past
non-magnetic. Once the entire edge is an even heat,
quench by placing the tip into the oil first, for a
slow count of 7, and then rock the rest of edge into
the oil for another slow count of 7. Continue rocking
the blade back and forth in this manner until all the “fumes” have
ceased. At this point slide the blade off the limiter
plate, and allow it to cool
COMPLETELY in the oil. Repeat the process twice more
for a triple quench.
Once the final quench/cool cycle is complete, grind
off the scale with a 120 or 220 grit, and get ready
to temper.
TEMPERING: Pre-heat
your oven to 350F. If you are using a kitchen oven,
don’t trust the dial! I also strongly suggest
an oven thermometer (I use two just to make sure).
Let
the oven cycle for 20-30 min to achieve a level, even
heat, and place the blade on the middle rack for
AT
LEAST TWO HOURS. Allow the blade to cool to room temp
between tempering cycles, and repeat for a total
of
three tempering cycles.
FINAL GRINDING: This
is where the rubber meets the road. To this point
you
have set everything else up for a fine convex grind,
and a nice flowing, distal taper. This can be a slow
process since your dealing with a blade that has
been
heat treated, and you should be grinding bare handed.
If the blade gets too hot to hold, then it is too
hot
period! I start with a fresh 50 grit belt, cleaning
up the tapers and then remove excess material from
the
flats of the blade. I usually will flat grind with
the 50 and then a 120 which will reduce weight and
thin
down the area just above the edge. Once I hit 220 I
go to a convex grind. I do this through a modification
I made to the grinder platen, where there is approx.
a 2” area that is slack just below the platen,
and above the lower contact wheel. Your goal at this
point should be for the edge to be sharp by the time
you finish with a 400 grit belt, as well as having
the
spine rounded and all sharp corners removed. (sharp
corners can, and often do cause blades to fail in
the
90-degree bend test).
Just to make things easier when hand sanding, I often
go over the blade with a 600 grit belt to get as many
400 grit scratches out as possible. Once you have completed
with the belt grinder, go to the bench and hand sand
out all the scratches with 400 grit paper. Even though
the ABS rules state that the blade need not be highly
finished, DO IT! I can usually tell when a potential
JS walks into my shop to test, as to whether or not
they will pass, based on the outward appearance of their
test blade. This is an outward and immediate indication
of how careful an individual has been with the overall
process. Especially if I have not met with the person
before. To date, my initial predictions have not been
proven wrong.
HANDLES/GUARDS/BOLSTERS: The
test blade is not required to be a fully finished
piece, and therefore guard and bolster are not necessary.
A couple of tips that will help with the bending
test
are..…….
1. Choose some type of micarta or phenolic for the handle
slabs. Both of these materials are very tough, and will
lend support to the tang area during the bending phase
of the test.
2. DO NOT use large handle bolts that force you to
drill large holes in the tang! This will only serve
to weaken
the tang, and could cost you dearly during the test.
I suggest holding the handle material in place with
epoxy, and at the maximum, a couple of 1/8” pins.
Maybe even just a couple of 1/8” brass pins that
are piened to hold the handles.
NOTE: The thing that will
get you through the test easily are paying close attention
to details! Superior heat treatment, proper distal tapers
to distribute the bending stresses, a fine convex grind,
and rounding all sharp corners. I personally like to
see a test blade that has been etched lightly in ferric
chloride to reveal the temper line and the grain structure.
This is also key, in that if the blade is not finished
to the point where a light etch will show the temper
line and grain structure, I believe it is not finished
enough for the test.
Many may insist
on using another type of steel, and that is fine.
As long as enough experimentation
has taken place to ensure all the desired characteristics
are there. In the past, individuals have passed the
JS test with other types of steel such as O-1 or
1095.
However, these individuals had taken the time and effort
to work out the "kinks". More aspiring
JS applicants have passed the test with 5160 than
with
any other steel..................that should speak
volumes!
This article
is intended as a general guide to creating a blade
that will pass the ABS JS
tests, and is in no way a guarantee of success. Much
depends on the individual bladesmith’s understanding
of proper blade design in relation to function, and
applying the concentration necessary throughout the
ENTIRE process of creating a test blade. These are
proven
methods from almost 20 years of bladesmithing experience,
and should be of much value to anyone interested
in
achieving their ABS Journeyman Smith rating.
Good Luck!!
Ed Caffrey, ABS Mastersmith
"The Montana Bladesmith"
.