All About Pucks

Nine questions and answers about that elusive object hockey players spend so much

time chasing.

Q: Who invented the hockey puck?

A: Originally, hockey players weren’t picky about what they used as a puck: a piece of coal, an apple, a knot of wood, even a hunk of manure. Eventually, a rubber ball similar to a lacrosse ball was used. But -- the story goes -- in the 1860s, when games started to be played in Montreal’s indoor Victoria Rink, the ball broke so many windows that the fed-up arena manager grabbed it, sliced off the top and bottom and threw what was left back on the ice. The players quickly discovered that the new shape reduced bouncing and made passing easier.

Q: Where are pucks made?

A: Most of the hockey pucks used in Canada are made in an old building in the west end of Toronto. The offices of Viceroy Reliable Group look like they must have in the 1950s. Not much has changed in the plant either, since the way Viceroy has made pucks over the years has undergone few refinements. The machines are the same, although in some cases the controls have been automated. “The nice thing about rubber technology is it hasn’t changed much,” says Todd Bruhm, general manager of Reliable. “The hockey puck has stayed relatively the same for 50 or 60 years. ”

Q: What’s in a puck?

A: As simple as a puck looks, it’s made of at least a dozen ingredients. Natural rubber, synthetic rubber and a filler (usually carbon black, or coal dust, which also gives the pucks their black colour) make up about 90% of a puck. Additives such as sulfur and an anti-oxidant make up the rest; they help in the curing process that gives the final product its strength and hardness.

Q: How is a puck made?

The ingredients are poured into an automated mixer called a Banbury and then pushed though a form in a process called extrusion. This result is soft logs of rubber compound roughly three feet long. These logs are sliced into slugs, called pre-forms, which are roughly the same size as a puck but a little thicker.At this stage, the pre-forms have none of the characteristics of the final product; in fact, a key can easily be dug into them. So the slugs are placed into molds and cured at 150 degrees C for about 22 minutes.

The pucks come out of the mold with knurled, or dimpled edges. The knurling gives the puck texture for better control on the stick. After the pucks are cured, the flash (the excess rubber left over from the mold) is trimmed. If necessary, logos are then applied, usually done by silk-screening.

Q: Are pucks made in Canada tested?

A: Viceroy, which started producing hockey pucks in the 1940s, can test its pucks for hardness and tensile strength, but usually only needs to when it switches suppliers. As long as the formula stays the same and there is no change in suppliers, the variation in pucks is negligible. The key to making a good puck is achieving the right hardness. If a puck is too hard, it will bounce too much and, in some cases, break the glass around the boards. If it’s too soft, it won’t respond properly and will deaden when it hits the boards.

Q: Why are some pucks made in China and Eastern Europe considered dangerous?

A: “Making pucks is not really a difficult process,” says Todd Bruhm, general manager of Viceroy. “There’s no challenge at all for us. The challenge is to set up quality control across the industry.” Some shipments of pucks made in eastern Europe have been too hard and have broken the glass in rinks. Some pucks from China have broken apart producing potentially dangerous projectiles. Bruhm believes that puck makers in these countries have trouble getting raw materials and that’s played havoc with their formulas as they’ve used inappropriate fillers such as clay. “The problem,” says Bruhm, “is all pucks look the same.”

Q: Does the NHL use the same pucks the rest of us do?

A: The NHL rule book states that pucks must be one inch thick and three inches in diameter and weig between five and one-half and six ounces. That’s the same puck normally used by all hockey players, except younger kids, who often use smaller, lighter pucks. Although Viceroy sells almost 2.5 million pucks in Canada each year -- more than any other puck maker -- it no longer makes the pucks used in the NHL. Those are made by Inglasco Corp., of Sherbrooke, Que., using a more expensive injection process that sees the rubber compound is liquefied, injected into a mold and allowed to set. According to Andre Blanchette, general manager of Inglasco, this method allows the puck maker better control over the final product.

Q: Why are NHL game pucks are frozen?

A: Timekeepers in NHL rinks keep a bucket of frozen pucks in the penalty box with them. When a puck is frozen, a thin layer of ice forms on it, reducing the friction between the puck and the ice surface. After freezing, pucks slide better, go faster and bounce less, making it easier to puckhandle, pass and shoot.

Q: How did the puck get its name?

A: In Shakespeare’s A Mid-Summer’s Night Dream, a mischievous sprite called Puck appears and disappears without warning and early hockey players thought their projectile had similar qualities.