WHERE THE FOILS ARE CHRISTMAS OPENS Washington Fencers Club at Silver Spring Intermediate Gym, Philadelphia (Route 410) and Chicago Avenues, Silver Spring. SATURDAY -- Men's foil at 9, men's saber at noon. SUNDAY -- Men's epee at 9, women's foil at noon. SALLE D' ARMES COMPETITION 1524-MM Springhill Road, McLean. DECEMBER 17 -- Men's saber at 10:30, women's foil at 12:30. Open house after the competition, about 6.

There was a time when a double-edged blade meant more than a close shave.

We remember Errol Flynn, Douglas Fairbanks Sr. or the greatest swashbuckler of all, Basil Rathbone, slashing through crowds, eyes ablaze, naked to the waist.

Now double edges are out, and today's swordsman uses a blunt-tipped foil and hides his torso under a quilted jacket. But he's still got the moves.

This weekend, the Washington Fencers Club opens its doors for would-be duellists to hear the clash of sabers and follow the flashing blades at its annual Christmas Open.

When they're not wielding a blade, Washington's fencers are nurses, research scientists, accountants or even ministers. Twice a week, they meet in private clubs like Salle D'Armes, Washington Fencers or D.C. Fencers to do battle and take lessons from the maitre d'armes (fencing master). For the privilege of using the club's facilities, they pay anywhere from $40 to $180 in annual dues.

Most cite the good year-round exercise as their motivation for keeping it up.

"Without the fencing I'd be immobilized by this time," said 59-year-old Herb Spector, who has been fencing for 44 years.

A 1941 collegiate All-American and member of five U.S. Olympic squads, Spector has arthritis in five joints, yet he brought home two medals from the Senior Olympics competition last July.

"It's a good way to get out some aggression," said Sam Crimone, a radiologist at Arlington Hospital. "I enjoy testing my talents against other people."

In addition to the physical exercise, Washington's fencers thrive on the mental exercise as well. The sport is often likened to "chess on your feet" because of the intense concentration it requires.

Bill Landers, chairman of the Washington division of the Amateur Fencers League of America, says it's the only sport he's found "that requires as much mental as physical agility."

Dan Lyons, of the D.C. Fencers Club, has been teaching the sport for almost 20 years. To become a champion fencer, he says, requires an "intensity that's ferocious."

Scott Bozek, United States champion in the men's epee in 1973 and 1976, started fencing when he was eight, and worked out steadily, four to six hours a day, through his college years.

In 1972 and 1976 he represented the United States at the Olympics, and in 1975 he brought home a gold-and-silver medal from the Pan-American games.

He is now affiliated with Salle D'Armes fencing club in McLean, and works as a desk officer in the Bureau of East-West Trade in the Department of Commerce.

"The prospects are much better for developing young fencers in this area than they were where I grew up in Massachusetts," he said. "There are several clubs available as well as fencing masters, whereas I had to work out at the YMCA and was just lucky to meet a person who was quite a good fencer, and worked out with me, free, for years."

Michel Mamlouk, president of Salle D'Armes, and a certified maitre d'armes, was born and raised in Egypt. "Fencing's been in my family for centuries," he boasts. "I was born with a sword in my hand."

When he's not teaching at George Mason University or Salle D'Armes, he manages to operate his travel agencies.

He's in the process of organizing a Fencing Masters Association, to certify teachers to educate the youngsters in high schools and colleges, so they won't have to go to Italy as he did to get his certificate.

But are the young people interested? Chris Turner, a 12-year old who fences with the Washington Fencers Club, wanted to take up the sport after seeing a demonstration at the Smithsonian.

His mother advised him to wait awhile (he was eight at the time) and then signed him up last year.

He's matter-of-fact in his reasoning."You're not gonna get killed like in football," he said. "There's no chance to get seriously hurt."

Indeed, Washington's fencing masters can recall only two serious injuries, both in international competitions, in their experience.

For all its violent origins as a form of combat, and its later history as a method of settling disputes with honor, the sport is now safer than most.

And while it may take time to understand the intricacies of its strategy, novice spectators can appreciate the speed and skill with which the competitors use their weapons. And they may find themselves seeing the gallant movie heroes of old behind those metal masks.