The Radius of Hollow (or RoH) is the depth of the cut in the bottom of the skate blade in hockey or figure skates that is made by the skate sharpener. The basis principle of RoH is the flatter the surface of the blade, the more glide and the deeper the cut into the blade, the more bite the skate blade will have on ice.
The profile (or rocker) of a hockey or figure skate blade refers to how much of the skate blade touches the ice. A smaller radius (measured in feet) is better for agility and maneuverability, and a larger radius is better for speed.
There are three components that make up a perfect skate sharpening – even blade edge height, sharp skate blade edges and a smooth blade finish. All three components are necessary for a perfect skate sharpening.
Without even edges on your hockey skate or figure skate, the rest of the skate sharpening process does not matter. There are many methods to check your edges after skate sharpening including the coin test and the use of an edge check.
It is important that your hockey skate or figure skate edges are sharp, clean and without burrs or nicks. A good skate sharpening will restore sharp blade edges so that the skate blade edge bites into the ice.
A smooth skate blade finish is a key factor in a good skate sharpening. A clean and smooth finish on the bottom of the skate blade contributes to a frictionless glide of the skate on the ice. A rough surface creates more friction and creates less speed.