Sharpening Angles of 25º-
30° are usually recommended for chisels and plane irons. These angles work fine for bench
chisels and as a beginning point for bench and block planes. However, increasing or
decreasing the angle may yield better results for other tools or applications. For
instance, heavy mortise chisels will hold an edge better if the angle is increased
to 30º or more. A 30° bevel often holds a better edge when working
hardwoods with a bench chisel. A fine, hand-held paring chisel with a lower
angle (25º) will cut and pare beautifully. Use the following in applying your
judgment to the situation: a higher angle produces a stronger but less sharp edge; a lower
angle results in a sharper, weaker edge.
Steel used in edge tools is a compromise. The characteristics of steel
directly affect the quality of a tool: too hard and it breaks, too soft and it wont
hold an edge. The trick is to use a steel that is hardenable, easily sharpened, yet tough
enough to resist chipping when encountering the occasional knot. What is needed is steel
with a high carbon content (.55% to .95%) and added metals such as manganese, chromium or
vanadium to improve hardening and wear characteristics. Our edge tools are manufactured
from high-carbon (.90%) manganese-enriched steel. Most importantly, the quality of our
steel is consistent because it comes from only one, long time supplier.
Sharpening Stones come in a
bewildering variety of materials and styles. Today's woodworker may well feel confused and
overwhelmed. Water or oil, diamond or ceramic, man-made or natural? Which is the
best stone to own?
We can start by answering the last question first. The best stone for all
purposes does not exist. However, there is good news. The best stone for a particular
purpose does exist. The answer to the question, "which sharpening stone should I
buy?" depends on first determining what kind of sharpening is to be done. Let's look
at the strengths and weaknesses of commonly available stones.
Oil stones This class of stones use oil as a lubricant to keep the
fine metal particles generated by the sharpening process from embedding into the surface
of the stone. The metal particles are kept in solution and as a result do not
"clog" or "glaze" the surface rendering it ineffective. Clogging is a
potential problem with all stones.
Manufactured oil stones are most commonly
made from either silicon-carbide or aluminum-oxide. Natural oil stones are usually
referred to as Arkansas stones, the softer variety, Washita.
The coarse and medium grit oil stones will
remove metal fairly rapidly. Because their surface is hard, oil stones wear very slowly
and stay flat for a long time.
The finer grit oil stones tend to remove
metal slowly and are prone to excessive "glazing."
Some woodworkers object to the messiness of
oil stones. Oily fingers and the fine project you are working on don't mix! I
have found that a mixture of water and dish soap works very well on oil
stones. Because they are hard and slow to wear, oil stones are perfect for
honing the narrow edge of a scraper blade.
Water stones Man-made water stones
have many advantages over other stones, and a few disadvantages. The advantages are:
- Very fast cutting action with a good "feel".
- Wide variety of grits are available.
- Fine grit stones leave a polished, very sharp edge
(difficult or unattainable with other stones).
- Generally affordable.
- These stones wear rapidly and must be flattened
- Water stones are somewhat fragile and must be stored and
Many professionals agree that water stones are superior for
sharpening chisels and plane irons, and for general shop use.
Ceramic stones Ceramic stones
are normally sold only in very fine grits and are commonly used in applications
where structural strength is necessary.
- They are quite hard and cut well when new but tend to become
less effective over time and need to be re-surfaced to restore cutting action.
- The ultra-hardness of ceramic stones insures a flat, long
Diamond Stones These "stones"
are made by bonding diamond material to a flat metal substrate. When purchasing check to
make sure the steel plate is flat.
- Diamond stones cut well and last a long time.
- They are the best choice for honing carbide tools.
- No lubricant is necessary and surface resists build-up.
- Diamond stones are generally expensive.
Woodworkers have different needs when it comes to
sharpening stones. They also have different preferences about the "feel"
of a stone. Try various stones and see what works best for you. Consider price, speed of
cutting, quality or sharpness of edge, durability and usefulness.