Popular Woodworking 2001-12 № 125, страница 37
About 150 years ago, Swiss watchmakers noticed that extreme cold changed the properties of their metal clock parts for the better. So after manufacturing their gears or what have you, some watchmakers would then store the parts in caves during the cold Swiss winters and let them freeze. Unwittingly, they had given birth to what is now commonly known as cryogenics. During the last century, toolmakers and metal heat treaters have explored what extremely cold temperatures do to tooling, metals and other materials. And they have come to some remarkable conclusions. For certain types of metals, cooling them to -320° Fahrenheit can make them at least twice as resistant to wear as untreated metal. The wear resistance is permanent. You have to treat your tooling only once, and it will remain that durable forever, experts say. And the price of cryogenically treating your tooling is becoming quite reasonable. We found that treating about four pounds of metal will cost you about $30 to $50. (If you treat a lot of items, the cost can be as little as $1 a pound — and prices continue to drop). Cryo labs themselves are also becoming more common because commercial heat treaters are investing in the technology so they can offer the service to their customers. If you live in an industrial area, you'll probably be able to find a cryo lab locally. But even if you live in the sticks, there are cryo labs you can ship your tooling to for treatment. So what's the catch? If cryo is so amazing why doesn't anyone sell cryogenically treated planer knives or router bits? Many of the manufacturers we talked to, including Freud, had experimented with the process in its early days and found it had little or no effect. That's not surprising, says Bill Bryson, author of the book "Cryogenics" (Hanser Gardner Publications) and the president of the company Advisor in Metals in Milton, New Hampshire. "Back in the 1970s it was a free-for-all, and it hurt the industry," Bryson says. "People were dumping tools in liquid nitrogen and they were cracking, or they weren't tempering the tools after the (cryogenic) process." As a result, cryogenics got a bad rap in the steel and tooling industry, Bryson says. Not only for the early mistakes that were made but because some people thought that cryogenics would hurt sales. If tooling lasted twice as long, they might sell only half as many tools. But during the last 30 years, heat treaters and cryogenic advocates began figuring out more about how, why and when cryogenics works. And today, most people in the industry acknowledge that it works well for certain types of metals, Bryson says, particularly the more complex alloys (more on that later). In the home woodworking market, we've seen only a few cryogenically treated tools on the market. A few years ago, Vermont American announced it would sell "Ice Bits," cryogenically hardened screwdriver bits. Hock Tools recently began offering a line of cryogenically treated A2 plane blades. The cryo blades cost between $5.50 and $12.50 more than the same-size high-carbon steel blades. And toolmak-ers Bridge City Toolworks and Steve Knight, owner of Knight Toolworks, also offer cryo-genically treated blades. But cryogenic treatment can help woodworkers with a lot more than plane blades or screwdriver bits, Bryson says. Just ask James Larry Poole of P & K Custom Cabinets in Lula, Ga. A couple years ago Poole sent out his carbide-tipped sawblades, router bits and shaper cutters to a lab for treatment. "It really makes them last longer," he says. "I had one sawblade in par- CRYO: IT'S NOT JUST FOR TOOLS ANYMORE Sure, cryogenics can make your tools last longer, but it also has a lot of other benefits, some practical and some wild. Here's a short list of claims we've gathered from books, magazine articles and the internet: • PANTIHOSE: Nylon stockings that have been cryogenically treated are less likely to develop runs. • GOLFING: Cryogenically treated golf clubs hit balls 3 percent to 5 percent farther. Cryogenically treated balls can be hit farther. • RACING: Hickson Engines has treated small-block Chevy engines and found significantly less cylinder wear during a racing season. Many other racing professionals have also used cryo. • FIREARMS:Treated rifles are more accurate. • MUSICAL INSTRUMENTS: Cryogenically treated instruments have a better tonal quality and the valves slide more easily. • GUITAR STRINGS: It doesn't even have to be the entire instrument. Some people treat guitar strings and say it improves their tone. • SPORTS: Baseball bats that have been frozen hit balls 2 percent to 4 percent farther. Many carbide tools are good candidates for cryogenic treatment. Before you treat your carbide-tipped saw blade or router bits, check with the manufacturer to see if the carbide is new or recycled — some companies use carbide recovered from old tools. For some reason, recycled carbide doesn't improve after cryogenic treatment. by Christopher Schwarz Comments or questions? Contact Chris at 513-531-2690 ext. 407 or ChrisS@FWPubs.com. 59 |
