Skate Sharpening 101

by Scott Noble

There is more than one way to sharpen skates. Unfortunately most of them are wrong. I once helped a customer who confessed that he attempted to sharpen his skates with a rotary tool. The result was of a lower quality than what he expected. In fact he was buying new skates from me as he confessed his gaffe. The simple fact is, there isn’t a good way to sharpen your own skates without a lot of money and practice. Rocket Skate uses state of the art Blackstone machines, the preferred sharpener of the NHL. But it takes more than a great machine. Years of experience and thousands of skates sharpened assure that you get a great edge every time.

Skate Sharpening: The Basics

It’s pretty obvious when you’re falling down that your skates aren’t sharp enough. But beyond that, skate sharpening is as confusing as the workings of spray cheese in a can is to the average hockey player. (Don’t take that as a jibe, I have no idea how that stuff works). Sharpening really shouldn’t be a mysterious process hidden in a back room. That’s one of the reasons Rocket Skate has the sharpening machine right where you can watch. (The other reason is that it didn’t fit anywhere else).  We’re happy to explain the process to you because knowing how sharpening works allows you to make an informed decision about what hollow might best suit you.

Perhaps I should back up a little though. I might have lost a few people with the term “hollow.” Let’s take a look at how skate sharpening works.

Essentially, a skate blade is sharpened by creating a perfectly rounded valley, centered on the bottom of the blade. This forms a pair of sharp edges at the outer extremities of the blades giving skaters control on the ice. This valley is the hollow, or more precisely the “radius of hollow.”

The radius of hollow can be varied from ¼-inch to 1 ½-inch, however most players will chose a hollow between 3/8-inch and 5/8-inch. Radius of hollow is the most important aspect of skate sharpening to understand. It’s really pretty simple. The bigger the radius, the shallower the hollow on the blade will be. Picture the radius as a wheel. A bigger wheel is going to be closer to flat than a small wheel. That is the impression the wheel leaves on your skate blade.

The depth of hollow changes the feel of the skates on the ice. A deep hollow such as 3/8-inch will give significant “bite” on the edges at the cost of glide. A shallower hollow like 5/8-inch will allow better glide with some loss of edge bite. Thus, if you’re tripping over your edges and landing on your head, the hollow you are using is likely too deep. If your skates are skidding wildly out of control, you probably need to go deeper on your hollow.

Radius of hollow describes the depth of the “valley” in the center of the skate blade. The diagram shown is a frontal view of the skate blade and holder showing an exaggerated view of the radius of hollow on the skate blade. An actual radius of hollow this deep would be the rough equivalent of skating on Velcro with thick wool socks. (For those scratching their collective noggins, you’d stick to the ice with skates sharpened this deeply.)

How to pick the correct radius of hollow

It’s all about personal preference. Telling someone what hollow will work best for them is like insisting that rocky road should be their favorite flavor of ice cream. While we all might think vanilla is boring, it’s the most popular flavor. In hockey, 7/16’s is vanilla. It’s what you get if you don’t want to make a choice. It might not be the best hollow for you, but it’s the one that most players get.

It takes most players a while to find the best depth of sharpening for their game. Like ice cream, you don’t know what you might like until you try it. Unfortunately, there isn’t any rule that says, “If you play this position and skate this hard, the perfect hollow for you is . . .” Trial and error is the only answer. But there are some factors to help make the proper choice.

Weight and skating ability are probably the most important factors in finding the proper hollow. Smaller and less experienced players will typically fare better with a deep hollow like 3/8-inch or 7/16-inch. These are the most popular recreational hockey hollows. Bigger and more skilled players will often prefer a shallower hollow such as ½-inch or 5/8-inch. A 400-pound man is going to get more bite with a shallower hollow than a 80 pound woman simply because of the increased pressure he puts on the ice. It’s also going to hurt more when he pastes you to the boards.

One factor that should influence the hollow of choice is the ice surface. In the summer many players switch to a shallower hollow because the ice is softer. Softer ice doesn’t require quite as deep a hollow for edge control. Conversely, harder ice will require a little more depth to get the same bite. If you don’t adjust your hollow, colder ice temperature can make your skates feel too dull, warmer too sharp.

Skating outdoors, however, can create something of a conundrum. Outdoor ice is generally harder on skates due to the increased amount of foreign objects on the ice. Outdoor rinks typically have very hard ice due to the colder climates, so a deeper hollow seems to make sense. However, deeper hollows go dull more quickly for a couple of reasons. First, there is less material at the skating edges. This leaves the skate blades a little more fragile in impacts and causes the edges to wear faster. Second, the greater bite that a deep hollow provides is much more noticeable when the edges start going dull. Playing on outdoor ice requires more frequent sharpening as a result.

Goalies are even trickier to narrow down. Typically aggressive goalies will use a deeper hollow than a novice goalie. However, overall the trend is for deeper hollows in goalie skates across the board. It used to be common for goalies to use a 1-inch or ¾-inch grind. 1-inch is fading from use. As goalies utilize their skates to aggressively slide across the ice in the half butterfly, deeper hollows are becoming a more common choice.

Still, it’s important to remember that goalie skates have wider blades than player skates. A ½-inch hollow on a pair of goalie skates has a similar depth to a pair of player skates sharpened at 3/8-inch. Also, with goalie skates using carbon steel blades as opposed to the harder Stainless blades on player skates, sharpening them deeper than ½-inch isn’t highly recommended. The edges simply won’t hold up very long at 3/8-inch on a pair of goalies with the kicking of posts and extra time that goalies spend on the ice.

How often should I sharpen my skates?

Regular sharpening is important to maintain the blades of the skate as well. It removes any light rust that forms on the runner’s bottoms and sides. It also helps to maintain the edges keeping nicks from becoming impossibly deep. Most importantly it restores the edges that allow skaters to propel themselves on the ice. Still the question of how often to sharpen skates is a common one.

More experienced players will notice as the edge on their skates starts to fade. But then if you knew that, you probably wouldn’t be reading this article, right? The general rule of thumb is every five to ten games. Some players sharpen their skates every game. To those players, I will be the first to say thank you very much. However, the practice is a little excessive and even wasteful. Unless you’ve stepped on something, you should be able to get several games from a sharpening.

Over-sharpening your skates doesn’t just cost extra money on the sharpening price—it wastes your steel runners. You should be able to get about 150 sharpenings out of your stainless steel runners. That’s 3 years of use sharpening once a week. I will let you do the math for more or less often. Replacement runners cost between $40 and $60 a pair.

Not all sharpenings are equal though. A less experienced sharpening shop could easily halve the total number of sharpenings. Some questionable sharpening methods might make this number even lower with established practices that are questionable in their very nature. Regardless, sharpening more often than required is a waste of money.

On the other hand sharpening less often than required is going to greatly reduce your enjoyment of the game. If you’re waiting until skates are so dull that you’re falling down, you’ve robbed yourself of the enjoyment you should have had that day. It’s akin to getting new tires on your car after you’ve had an accident or blowout. Now that doesn’t make much sense, does it?

Most players should consider sharpening their skates once or twice a month. Players skating twice a week should have their skates sharpened monthly. Those playing or practicing four or five times a week should typically have their skates sharpened twice a month.

What makes a good sharpening?

We’ve already discussed the radius of hollow. This is a pretty important factor that will significantly change the feel of a pair of skates. Changing hollow will be noticeable for most players within 1/16 th of an inch. Writing your preferred hollow on the bottom of your skates is a pretty good idea. It isn’t foolproof, since fools are so ingenious, but it can help.

Unfortunately, some automatic and semi-automatic machines have highly inconsistent controls for Radius of Hollow. Top loading sharpeners have a number of problems, this being a major one; some of these sharpeners indicating a 7/16-inch hollow are actually sharpening at ¼-inch radius. That might not sound like a big deal, but it’s so deep that it’s more like wearing crampons than skates. You could use your skate blades to cut tomatoes for a television commercial at that depth.

At least as important as getting the proper hollow on your skates is having the hollow properly centered. If the technician fails to properly center the skate on the wheel, the edges will be uneven. A few thousands of an inch in difference from one edge to the other is enough for many players to feel something wrong. An out of square skate like the one on the diagram on the previous page makes for a pretty miserable day on the ice. The poor skater who uses a pair of skates that are out of whack like this one is going to be tripping on the right edge which seems far too sharp. The left edge will feel so dull, he’ll be slipping off it and falling. Falling down and skating aren’t exclusive, but they sure aren’t the same thing.



At Rocket Skate every pair of skates is hand sharpened on state of the art machinery. The stone is dressed to very tight tolerances assuring that you get the hollow you ask for. Most importantly, every skates is quality checked for square and center. If a skate doesn’t meet exacting Rocket Skate standards it gets fixed before it goes out the door.

What makes a bad sharpening?

Some shops cross-grind every pair of skates they sharpen. Essentially this is a method in which the blade hollow is returned to flat on a vertical wheel before the skates are sharpened on the horizontal wheel to put the hollow back in. For the most part this doesn’t make much sense. This is akin to shaving your head and waiting for the hair to grow back each time you want to change your hair style. It’s as old fashioned a method as it is just plain stupid.

Cross-grinding skates can be a useful technique in several instances. It isn’t a bad way to start off a new pair of skates as the edges are often very uneven from the factory. It’s also not a bad thing once in a great while when a pair of skates has serious gouges from something like walking on concrete or jogging in gravel while wearing them. Cross-grinding is also very useful for changing the contour or rocker of a pair of skates to change the balance of the skates. However, it shouldn’t normally be used for sharpening skates.

Here are the problems with cross-grinding. Cross-grinding for every sharpening changes the rocker very rapidly. Half a dozen sharpenings using this method can create a notable change in the shape of the skate runner when skates are cross-ground each time. Why? The amount of material coming off the skate when cross-grinding every pair is many times that of what a good quality sharpening might take off. The natural contours of the skate create points where the sharpening tech will inadvertently apply more pressure and ruin the rocker of the skates.

The long term effect is a flat rocker on the skate blades. This creates a serious reduction of on ice maneuverability as the rocker becomes flatter and flatter. Perhaps even more important is that the life expectancy of a runner with this method drops from 150+ sharpenings to about 50. Ask your shop if they cross-grind every pair. If they do, find someone else to sharpen your skates

Some shops rely on technology rather than expertise. Automatic sharpeners and semi-automatic sharpeners seem like a good idea. In theory these would offer consistent sharpenings more perfect than a flawed human could achieve. However, they haven’t yet designed a machine that can replace a skilled operator. The problem with these machines is that they rely on gravity to apply constant pressure on the skates. Like cross-grinding every pair of skates, this creates issues with the rocker. Because the heel and toe of the skate are curved, these spots end up spending more time on the wheel. With gravity applying the pressure, there is no way to lessen the effect of this on the skates.

The end result of sharpening skates with an automatic machine is rounded toes and heels. The skate blade essentially becomes gradually shorter reducing the player’s gliding ability, reducing balance and eroding stability on the ice. If your skate shop uses an automatic or top-loading machine you might want to find another place to get your skates sharpened.

Rocket Skate’s sharpening techniques aim to protect the rocker of your skates. Only the best equipment and years of practice make this possible. Don’t trust your skates to inexperienced techs, outdated methods or yet to be perfected technology. You paid for your skates, now expect the best sharpening you can get.