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Recreational Figure Skating FAQ - Blades

Archive-name: sports/skating/ice/rec-skate/blades
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Last-modified: Sep 4 2004
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5. Blades

Blades are commonly made in 1/4 inch lengths. Blades also have
different widths and radii, as well as different configurations of the
"bulge" (spinning area) and toe picks. These all have major effects on
the way a blade "feels". A list of commonly available blades and their
characteristics and prices is given in Appendix 1.

Figure skate blades start out in three separate parts. TOE plate. HEEL
plate and the part that actually does the work on the ice. These are
punched out on large presses. The blades are blanked out of long
strips of steel which vary in Carbon content depending on the quality
of the particular skate blade that is being made.(i.e. a Majestic
would have a lower grade of steel than say a Phantom or Pattern 99
Although the steel used for all blades hardens to the same standard,
the better grade would keep its edge longer(under equal conditions).

Before the three parts are put together to make the skate the blade
section is hardened. This is done in large quantities hung on a frame
and lowered into a high temperature salt bath for a set period of time
to be evenly heated and while still glowing red are quenched in an oil
bath. The shock of the sudden decrease in temperature causes the steel
to harden . However, the hardness at this stage is too brittle, so the
blades (still on the frame) are put into another salt bath of a lower
temperature to temper to about what is called 60 degrees on the
Rockwell scale. When cooled they are removed from the frames fed into
a machine that grinds them to a set thickness.

The toe and heel plates (already ground) are then brazed to the blade.
There are two methods of joining the parts together. John Wilson
products are all silver soldered. This is a fairly low temperature
braze achieved by electrical coil induction which causes the heat from
the brazing to travel down onto the blade reducing the hardness to
about 40 degrees Rockwell 'C' for about halfway but leaving the lower
"working" half (about 5/16'') still at 60 degrees. Mitchell & King on
the other hand silver solder theirs but the top quality blades such as
Phantom, Gold Star etc. are hand brazed with bronze. This operation
creates a lot more heat therefore the blades, by no means soft could
be a bit patchy in their hardness. They are then set into an induction
coil, electrically heated, rehardened and tempered about halfway up
the blade.

You can tell if your blades are hand brazed. If you look at them you
will notice that where the toe and heel plate joins the blade there is
a very large radius. This method is very strong. Silver soldered
skates will have a small bead of braze so the radius will be much
smaller. However silver solder flows well and fills gaps readily. So,
whichever method is used there will still be 5/16'' or more of correct
hardness.

The assembled blade is now chrome plated, the profile is ground on and
the chrome is removed from the edges by grinding. This is the line
that you see each side of the blade edge. This is removed so that
hardened steel and not chrome is at the working surface. There is of
course extensive polishing and inspection before shipping.

5.1 Buying new blades

The blade length denotes the measurement from the front of the sole
plate to the back of the heel plate. Measure the length of the sole
from toe to heel and fit blades which are 1/4 inch less in length.

Some people believe that they have to buy blades that are super
expensive in order for them to become great skaters. You should buy
well-built and *appropriate* equipment. Skaters gradually upgrade
their equipment as their needs change, for example a skater may need
to upgrade skates when they move from basic skating to their first
jumps or from double to triple jumps. Advanced blades require the
skater to perfect his/her technique.

Top of the line blades are designed for very advanced skaters.
Advanced free-style blades have a longer radius and have *large* toe
picks. Also, the portion of the blade that is used for spinning is
much shorter than on intermediate blades; that means that unless you
are perfectly balanced and positioned going into and during the spin
you will start rocking on the blade. Intermediate blades like the MK
Professional, Coronation Ace, etc. provide you more "room" to make
corrections and continue spinning even if you are slightly off
balance.

Just because the MK Gold Stars are typically over $400 does not mean
that they are inherently better blades than MK Pros or Phantoms.
Starting with MK Pro and Coronation Ace lines, the blades are all made
using much the same materials and manufacturing process as described
above. To put it succinctly, certain blades are more expensive simply
because of supply and demand and a few slight design modifications
like side honing which makes them marginally more costly to produce.

5.2 Three ways of checking used blades:

1. Look at how thick the dull strip is on the sides of the blades
along the edges. They were three or four millimeters when new. If
they're now thin, then your blade has been sharpened many times. The
concern here is that the rocker may be distorted after many
sharpenings, and it is almost impossible to restore without
specialized equipment.

2. Put the skate upright on a table, and check the position of the
bottom toepick. The blade should also be touching the table within one
or two inches of the toe pick. If the blade touches the table further
back, it means that the toe-pick is too low (probably a consequence of
successive sharpenings). If the blades touches closer than 1 inch, the
master toe-pick may have been ground off. In this case, the blades
will be useless for learning spins and jumps.

3. Ask the skate sharpener at your rink to examine the blade. They can
tell you if the blade is bent, incorrectly mounted or obviously
damaged by abuse or bad sharpening.

If the only problem is that the toe pick is too low, ask your shop to
grind it some to raise it. Never have the bottom (master) tooth ground
off your blades unless you only intend to use them for figures.
Otherwise the tooth fairy will never forgive you!!

5.3 Mounting

Skates with improperly mounted blades can be virtually impossible to
skate on. The blade must be correctly positioned and aligned on the
boot. To avoid twisting the blade, the boot heel and sole contours
must match the blade mounting surfaces. If not, the surfaces can be
trimmed with a rasp, or shims can be added between the blade and boot.

Briefly, this is how your skate shop will mount the blades:
1)find the center of the tip of the sole and the center of the heel
and draw a line joining them.
2) place the front of the sole plate of the skate blade in line of the
front of the sole of the boot, and maintain the skate blade along the
line drawn. This will place the blade between the big toe and first
toe.
3) Screws may be placed only in the slotted holes, so that you can try
them and make minor adjustments (a blade position slightly closer to
the big toe is sometimes favored). Don't do any jumps until the best
position of the blades has been found and more screws have been
inserted.

5.3.1 Problems with warping

1. The blade may have shifted sideways slightly when the front or back
pair of screws were tightened on the temp mounts, warping the blade
from front to back.
2. The holes for the permanent mounts might not be positioned
perfectly, warping the blade as in #1 above.
3. The heel might not be perfectly level or flat with respect to the
front of the boot. Old screw-holes may have created bumps on the heel.
Or the boot might have been manufactured with an uneven heel. Such a
heel will twist the blade.

5.3.2 Checking for mounting problems

If you have trouble getting good edges, first have the blades checked
to make sure they are straight, properly sharpened and mounted
perpendicular to the sole. If the problem persists, have someone watch
to see if your blades "make snow" as you try to skate on the edge in
question. If they do, this may point to a mounting problem which can
be corrected by a slight shift of the blade mounting. You will need to
tell the person remounting your blades which edges you are having
trouble with.

You can also check if your blades are mounted correctly by yourself
(you need recently sharpened blades for this test to ensure that the
edges are even):
1. Find a clean patch of ice
2. Gather some speed and glide on two feet on a straight line. Keep
your body upright. Your feet should be directly under your hips.
Try this several times, both backwards and forwards
3. Go back and look at the the traces: if the blades are set
correctly you should get a set of double lines for each foot. If
one of the lines is consistently thicker than its mate (or if
there is only one line), it means that your weight on that blade
falls predominantly on the edge tracing that line,i.e., the blade
is unbalanced.
4. If you are leaning mainly on the inside edge, have the blade
shifted to the inside and vice versa. You probably only need a
small shift -try moving it by 1 or 2mm and then repeat the test

5.4 Rocker

Rocker is the curve of the blade from toe to heel, and is based on the
arc of a circle with a given radius. Thus, if you drew a circle with a
7 foot radius and placed a blade with a 7 foot rocker along the inside
curve of the circle, it would line up with the tracing, at least at
the rear (tail) of the blade. The curve at the front, behind the toe
pick is somewhat sharper. It is this difference of curvature which
allows you to turn and spin on the front of the blade.

The smaller the radius, the more rocker (amount of back and forth
rocking motion you can get when standing on the blade) it has. With
small radius blades, you can do turns with less chance of falling as
there is less blade on the ice. For the beginner, a 6' radius is fine
as, among other things, it is very forgiving in the toe pick
department -- you really need to lean way forward on them to catch the
picks.

The bigger the radius, the flatter the blade. This will generate more
speed as more of the blade contacts the ice. You will want a flatter
blade (7 foot or more) as you become more advanced. When you start
learning jumps, you will find that you need good edge control. Because
you have more blade on the ice, you can start to prepare your body
position for takeoff without falling off the edge so easily.

5.5 Grind or hollow

Hollow or grind refers to the concave surface on the bottom of a
correctly ground blade. A small radius creates edges that will dig
deeply into the ice, while a larger radius digs in less, but glides
more freely. A hollow with a 5/8'' to 3/4'' radius is recommended for
beginners and "all purpose" skates. This hollow will allow you to
sense how a proper edge should feel, and at the same time be forgiving
in things like T-stops. The weight of the skater will also affect how
deeply it should be ground: Usually children will need a deeper hollow
than fully grown adults.

Finally, the width of the blade is yet another factor to consider: A
deep hollow with a 3/8'' or smaller radius will be UNFORGIVING on
freestyle blades, unless you are a child or have a very petite frame.
This type of grind may yields crisp and fast 3-turns, ability to hold
a very deep edge when landing jumps, and allows for fast spins IF you
have them centered. An uncentered spin on deep edges will cause you to
travel. See about traveling. On the other hand, such a small radius
will be ideal for dance or hockey blades: Because these blades are
narrower than freestyle blades, the need a deeper grind to get the
same grip on the ice.

A shallow "figure" hollow with a 1'' or larger radius will require a
more correct lean to prevent skidding and requires more frequent
sharpening, but yields an easy glide and clean tracings.

5.6 Advanced blade features

5.6.1 K-pick

The K-pick design consists in a set of extra 3-4 picks to the side of
the standard toe-picks. This feature is supposed to provide more
control and better anchorage to the ice on toe-jumps. According to
blade manufactures, the jump height can increase by 5-10% and the jump
length by about 20% on toe loops and flips. No significant
improvements in height and length have been reported for the Lutz,
although the improved stability on the take-off supposedly makes for
more consistent jumps. Many freestyle blades models, particularly at
the high end range, are available with K-picks.

5.6.2 Side honed, parabolic and tapered blades

Most skating blades have the same constant width along its full
length. However, some advanced freestyle figure skating blades have a
concave section ("side honing"). Side honed blades are thicker at the
stanchions and the edge stripe and thinner in between. You can tell
side honed blades because reflections appear inverted.

Another modification to the edge profile found in advanced blades is
"tapering". Tapered blades are thicker at the front near the toepicks
and thinner at the tail, i.e. the edges are not parallel. Parabolic
blades are thinner in the middle section and thicker at both ends.
Some models or custom made blades can be both side-honed and tapered.

These modifications make the blade lighter (because of the removed
steel) and supposedly provide a better grip on the ice. Not
surprisingly, the more laborious manufacturing process translates in a
higher price. Whether they actually provide any real advantage is a
matter of discussion.

5.7 Sharpening explained by an expert

Take your skates to a pro shop or ask some regular skaters at your
rink where they get theirs sharpened. Skate sharpening is NOT a
do-it-yourself project! Skates are expensive and it only takes one bad
sharpening to turn them into scrap metal!
1) You have to know and trust your sharpener,
2) Your sharpener has to know you and your needs,
3) You have to stand guard over your skates until they are sharpened
by the proper person.

Skates properly sharpened will have a smooth concave grind accurately
centered along the length of the blades, edges squared (parallel to
the bottom of the boot) and level with each other (inside edge at same
height as outside edge) for the length of the blade. Proper sharpening
will maintain the correct rocker for the life of the blade.

Freestyle sharpenings will have typically a 1/2'' radius concave grind
and will be in a sharp condition. The edges of a deep freestyle grind
have the great advantage of holding jump landings on hard or soft ice
and also will outlast a shallow grind by a considerable amount of
time. They will also hold landings on missed jumps and give the skater
that extra split second to catch their balance and avoid unnecessary
falls. A sharp deep grind takes a little effort on the part of the
skater to adapt but is well worth the effort and once adapted to it
will be no problem in future sharpenings.

Figure sharpenings will have 1 1/4'' radius concave grind and will be
in a medium sharp condition. The figure grinds are extremely smooth
and flow freely on the ice. More shallow (greater radius) grinds have
extreme flow on the ice but are usually suitable only for the more
advanced skater.

Combination sharpenings will have 3/4'' radius concave grind and will
be in a medium sharp condition so that the skater can skate figures
with ease or they can be used for general skating. The grind will be
of smooth finish and will flow quite freely on the figures (although
not as freely as a true figure grind). This grind can be used for all
jumps and spins and will hold well while blades are in a sharp
condition. This grind is also very suitable for occasional skaters and
some dancers; and is also good for adults to start with.

Skates should be resharpened before they become so dull that you begin
to slip on hard ice (eg: not flooded since last night). This will also
minimize the adjustment you need to make to your newly sharpened
skates. Nicks in the blades should also be attended to. Bad nicks in
the edges will ruin the finest sharpenings.

When the blade is ground down a long way after many sharpenings, the
relationship between the bottom pick and the blade edge should be
maintained by removal of steel from the pick. There should be about
1/2'' lift at the heel before the pick makes contact with the ice.
Just because your blades are ground down past the line of chrome
plating, that is not an indication that you need new ones. There is
still lots of life left as long as the sharpener replaces that "line"
and adjusts the pick height.

Beware of how some shops do their sharpening: Some shops flat-grind
the blade first, and then hollow grind. This wears the blade at an
accelerated rate.

5.8 Maintenance

There are two kinds of blade covers, hard rubber/plastic guards and
terry-cloth "soakers". The plastic guards should be worn *any time*
you step off the ice. Even "safe" rubber mats or carpets accumulate
dirt and grit from the shoes of pedestrians, and this grit will nick
and round off the fine edges of your blades much faster than gliding
across the ice. Do not leave them on your skates between sessions as
they will trap water and cause your blades to rust.

The cloth soakers are put on after you have removed your skates and
wiped them dry with a rag. They protect your blades from bumping in
transit and wick away any condensation so your blades won't rust. If
you still have problems with rust or want to store your skates, rub a
drop of oil or Vaseline along the bottoms of the blades.
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