Figure
Generally made from carbon steel of approximately 4mm thickness, figure blades have a toe pick at the front and a short tail at the back. Higher level blades will have bigger toe picks and may be case hardened ( ie higher carbon content in the outer skin. When the blade is heat tempered, the outer shell becomes much harder than the main body, but the blade remains flexible and not brittle.)
Speed
Speed skate blades are very thin, just 1mm wide and are flat ground, usually by hand. This means that they have no hollow in them at all, and the skater needs to learn to use the blades correctly to cut an edge on the ice. Since the skaters only ever turn left during a race, the blades may be offset to the left to allow the skater to lean deeper into the turns.
Hockey
Hockey blades are usually made from stainless steel of around 3mm thickness. Some low end blades may be carbon steel, which is a harder metal, but prone to rusting if left wet. Higher level blades may be constructed from 2 different metals, an aluminium upper for lightness, and a steel lower section for hardness where the blade contacts the ice. Hockey blades are mounted in a plastic holder, the higher level ones having replaceable blades.
Rocker
The base of the blade will have a slight curve to it. This curvature is know as the rocker, and if you continued the curve around to make a full circle, the radius of the circle would be 7’ or 8’. On a figure skate, 11’ to 13’ on a hockey skate, and over 20’ on a speed skate.
On a figure skate ,the front part of the blade has a different rocker, which would form part of a tighter arc called the Spin Rocker. As its name implies it is this area the skater will use to spin on the ice.
The rocker must be smooth, with no high or low spots, as it is this feature which allows the skates to turn so freely on the ice, and as usual there is a trade off. The more curved the rocker is, the easier it will be for the skater to turn, but the skate will be less stable front to back.
Hockey skates are often specifically profiled to suit the position on the team where the player plays. Profiling may even include a completely flat section on the main skating surface to give the skater extra speed in the glide. Some sharpening techniques involve dressing the front half of the blade to a deeper rocker than the back. This gives improved glide at the back of the blade, coupled with good turning ability at the front.
Radius Of Hollow (ROH)
If you were to cut through a properly honed ice skate blade vertically (not recommended), you would find that the base of the blade has a curved groove ground into it.
This groove is formed by a spinning abrasive wheel which has been dressed so it forms part of a circle, the radius of which is known as the Radius of Hollow (ROH)
Skates can be ground to anywhere between 1/4” ROH and 1” ROH, and even 2” in some extreme cases.
The ROH has a major impact on the feel of the ice skate on the ice. A small ROH (1/4” to 1/2” will give good sideways grip, at the expense of glide performance because the blade cuts deeper into the ice.
A larger ROH, 3/4” to 1” will give better glide performance at the expense of sideways grip because the blade does not cut into the ice so deep. This is more suited to novice skaters who are still learning how to stop on skates. A shallower hollow will make it easier for the blade to skid sideways, and since stops generally involve skidding one or more of the blades over the ice, stops are easier to master The blades will also need sharpening more often as the blade will dull quicker.
In the days of true figure skating, ROHs of 1” to 2” were favoured as the skaters were given marks for the pattern they cut on the ice. If both edges cut in on a curve they would lose points, hence the desire for a wide, virtually flat blade. Nowadays it is very rare for anyone to skate with a hollow greater than 9/16”
The best ROH for you depends on a whole range of factors.
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Your weight - The heavier you are the shallower the cut you will need. Light people will need a deeper ROH as the blade isn't being pressed so hard into the ice.
Ice Temperature -The colder the ice the harder it gets. Harder ice needs a deeper ROH for the skate to get a hold. The temperature tends to vary from rink to rink and season to season.
Skill Level - Experienced skaters usually prefer a deeper ROH as they take corners faster and need the additional grip this provides.
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Discipline - Freestyle, dance and pairs skating all incorporate different techniques and consequently, the all have different blade requirements.
For beginners and improvers the ROH is generally set to 1/2” or 9/16” as this gives the best compromise between grip and glide performance, and will help you perfect essential skills as you learn to skate.
Ice Skate Sharpening
Ice skate Blades should be sharpened using a machine built specifically for the purpose, it really is not practical to do it by hand. Good quality skate blades are made from very hard metal which only the sharpener’s abrasive wheel will come near.
The machine will grind the hollow precisely in the centre of the blade ensuring that both edges are at exactly the same height.
At Everglides we use the Prosharp AS2001 (pictured above) which has proved itself as the leading skate sharpener on the market today. Both Hockey and Figure skaters have appreciated the super smooth finish and precisely level edges that the machine produces, and the many times world and european champion Evgeni Plushenko, who owns a Prosharp machine himself says,”Im very happy and satisfied with the machine that I got from ProSharp and I will use and trust only to ProSharp when sharpening my skates before trainings and competitions.”
Skate blade sharpening requires a significant degree of skill from the operator. Computer controlled units like the one above are a much safer option. Most of the commercial machines available are manual units and need to be very carefully set up and operated.
Some common problems
Off centred hollow - The hollow in the base of the blade must be absolutely centred on the blade. Since blades come in a variety of widths, this is not as easy as it may first seem. A simple way to check if your blades have been sharpened accurately is to turn the skate upside down and balance a large coin on the bottom of the blade. The coin should sit flat on the blade. If it rests at an angle, the edges are not level!
Uneven Rocker - Good sharpening of the blade will follow the existing rocker shape precisely, and preserve the spin rocker profile at the front of the blade. The spin rocker on an advanced figure blade is very subtle, and poor sharpening can easily flatten this vital section of the blade.
Detempering
If the blade is left against the abrasive wheel for too long it will overheat and when it cools, the metal will detemper (soften). If your blades come back with areas which look to have a blue sheen, then you can be pretty sure that they have been overheated.
Damaged drag pick
Good ice skate sharpening will avoid the drag pick altogether. No metal at all should have been removed from the drag pick during regular sharpening. It is possible to re-align a worn drag pick, or raise it slightly to compensate for over sharpening of the base of the blades, but this is a highly skilled operation and must be carried out by a competent technician.
Rounded tail
Unless the sharpener is being very careful, it is easy to round the tail of the blade off. The blade edges should run all the way to the back of the tail, and not round off.
Weave Pattern
Most sharpening wheels will leave a pattern on the base of the blade that looks a little like woven fabric. This should be almost invisible, if there is deep weave cut into the blade, it will introduce unnecessary drag and make the blade run more slowly than it should.
Blade Edges
It is easy to tell when your skates need sharpening, first and foremost because you will not have enough side grip on the ice, and the skates will tend to slide out from under you when a sideways force is applied to them. Once you’ve skated on sharp blades, you will never want to skate on a blunt one again.
Some other simple tests are:
Gently Run your thumb nail gently across the blade, it should be sharp enough to just scratch it.
Look at the blade under a bright light source (ie sunlight!) there should be no noticeable light reflected from the edge.
Professional Blades
Recent developments in ice skating technology have introduced some new features to the blade design.
Blade Construction
Most modern skate blades are made from carbon steel and should have been heat hardened. Cheaper blades tend to be soft, and some we have found have not been heat hardened at all! It will either have been polished to a bright silver finish, or it will be electroplated with either Chrome or Nickel to make it more resistant to rust.
More advanced blades may have been ’Case Hardened’, a process which involves getting more carbon into the outer shell of the metal, so when it is tempered, the outer shell goes very hard but the blade doesn’t become brittle. If the whole blade was hardened to this degree, the blade would be prone to snapping during moments of high stress.
Surprisingly few blades are made from stainless steel, as this metal is softer than carbon steel so would require sharpening more often.
Carbon Steel and Water
As carbon Steel will rust if exposed to water it is important to dry the blades as soon as possible after skating, and to store them in a dry location.
Most skaters will use blade soakers which fit over the blade to absorb any moisture and keep the blade from rusting.
Revolution
John Wilson and MK blades have developed a carbon fibre topped blade called the Revolution. The benefit of this blade is the reduced weight, less weight means more height on jumps.
Cross Cut
The toe pick is machined diagonally, which gives little pyramid shaped sections at the sides of the picks. This gives more bite on the ice, and reduces the likelyhood of the blade slipping when the skater is performing toe assisted jumps.
Side-honed
The blades have concave sides machined into them from top to bottom. This creates a more acute angle at the edges where the blade meets the ice, so the skater gets more bite on the turns without adding extra friction on the straights.
Titanium
Some blade manufacturers have developed blades made from Titanium, which is very light weight but strong. These blades have steel runners, as it is not possible to sharpen Titanium on a grinder’s wheel.