You’ve got to think about what you want
the end product to be used for and that
will determine how much you want to
temper it out. Tempering is done to a
straw-like, bronze k ind of colour. If it goes
purple you have gone too far. When it is a
darker bronze colour that means it’s a bit
more tempered and has softened up a bit,
so is less likely to break. If you temper it
too much it won’t hold a good edge.”
- Do two or three tempering cycles:
“I normally do two, two-hour cycles
at 200°C with gradual cooldown
between cycles in the kitchen oven.
This works for the steel I use.”
Let the steel cool slowly in between
heating. This allows it to normalize and
keep its hardened structure.
Grind
Josh notes: “I don’t have a belt grinder; I
do it all by hand with an angle grinder.
You don’t need a $2K belt grinder to make
a knife. All my grinds are convex grinds,
which makes a strong, sharp blade. It
depends how much of a convex you put
on it. You make the edge a bit thinner for
a slicing tool and thicker for an impact
tool. Make the edge too thin on an impact
tool and it can fold. You are trying to
balance hardness and edge retention with
longevity of the blade.”
The grind should follow the shape of
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have got a sharp point where you need it
but straight away the support you need
behind it.”- On the angle grinder, grind the blade
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80, and 120 is as far as they go.)
“The rough work you start off with the
40-grit pad to get the majority of the bevel
down,” Josh says, “but you have forged it
down anyway so you don’t have to take
off a whole lot of steel.”
Keep it at a constant angle so you are
not rolling it. It does take practice. Bring
it to wh at i s r ig ht for t h at pa r t ic u l a r to ol.
The metal gets hot, so cool it in water in
between passes of the grinder.
It is ready for the whetstone when you
can feel an edge.Sharpen
- Sharpen the knife at around 15
to 20 degrees on a whetstone. To
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impregnated with polishing paste to
remove any burr and leave a razor-
sharp edge.
And there you have it, a good all-round
utility knife that will perform all the tasks
that you could ask of a knife this size.
belt grinder to make
a knife”Putting the final edge onWatch out! Josh wields a parang and a
double-bit axe