lotus

previous page: 4.6 Children's skates
  
page up: Recreational Figure Skating FAQ
  
next page: 5.1 Buying new blades

5. Blades




Description

This article is from the Recreational Figure Skating FAQ, by Karen Bryden with numerous contributions by others.

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.

 

Continue to:













TOP
previous page: 4.6 Children's skates
  
page up: Recreational Figure Skating FAQ
  
next page: 5.1 Buying new blades