Jeweler David Yurman talks over ring sizing with employees at his office in New York. Craftsmanship is what ultimately brought Yurman into the world of fine jewelry.

David Yurman lacks a certain polish — and that is his charm.

As one of the world’s few household-name jewelers, Yurman could have his feet up on the desk, wear the finest suit and flashiest gems, or be or too slick to say anything juicy in an interview. But on this day, at least, that’s not Yurman’s style.

With a simple cable-style bracelet that’s become his signature dangling from his wrist, he walks around his impressive 58,000-square-foot office space in black jeans and a pullover sweater, greeting everyone by name. Yurman spends the most time hovering over those working on Computer Assisted Design terminals, suggesting adjustments here or there.

It seems the size and scope of his still-private company hasn’t sunk in yet. He lingers over photos from the early days: holiday parties with the same stone setters still working in the back today, and, especially, his first ad campaigns, which he says have always tried to sell the idea of democratized luxury.

But in a sign of his own changing times, newer ads on the wall star the likes of top models Kate Moss, Amber Valetta and Natalia Vodianova instead of anonymous faces.

Growing this business — now with 21 of its own retail shops, high-traffic counters at luxury stores, and expansion into fragrance and eyewear — has always been about one thing: passing on opportunity to his son, Evan, giving him the jump-start to a life that Yurman, who was out earning his own income at 19, didn’t always have.

Craftsmanship is what ultimately brought him into the world of jewelry, but that was after indulging in a cross-country hitchhiking trip to California, more than a few late nights with the beatniks and a passion for whittling.

Yurman, 67, says he always believed he’d be an artist, specifically a sculptor — and he was for a while. “At 16, I learned how to use a blow torch. I was a bad student but I stayed focused at the welding table. I knew I liked to make things.”

The other skills he remembers from his Long Island, N.Y., childhood were running track and dancing. Business, branding and the fashion industry never fit into the equation.

He got a motorcycle and hung out with an eccentric crowd, and Yurman began using his sculpting and welding talents to make belt buckles.

It was enough to start him on a bona fide career path, he says, even if it was one that required driving to every craft show he could find — probably 40 a year. At first, he’d pull up in a ’62 Cadillac among all the VW Bugs and beat-up Volvo wagons. He stood out, he recalls with a laugh.

Later, becoming more a part of the craftsman scene, he’d get into an old Saab and wear Birkenstocks once he and new wife Sybil moved to a Putnam Valley farmhouse in upstate New York.

But Sybil, a painter, wasn’t a fan of this nomadic craft-show life. She did, however, love the one-of-a-kind pieces of jewelry he started making for her.

So did a Manhattan gallery owner, who asked the Yurmans one night at an exhibit opening if a particular piece was for sale. He said no — the piece was so personal; she said yes — seeing the start of a business.

He knew better than to argue, Yurman says, and he soon returned to New York City, where he had earlier apprenticed with sculptors Ernesto Gonzales and Jacques Lipschitz. “I came to the city kicking and screaming to follow Sybil. But we made the decision to move to the city so we could sell ‘Main Street.’ We got into fine jewelers and then (Henri) Bendel’s and then Neiman Marcus and Saks. We still sold a handful of craft stores.”

That was more than 30 years ago, and the brand now offers about 300 new pieces a year in addition to scores of the classic silver-and-gold cables decorated with colored stones. Yurman said annual sales total more than 700,000 units.

It can takes less than six months for an idea to become a salable piece, but sometimes it’ll stew much longer if Yurman isn’t feeling in his gut that a design fits into current tastes — and he thinks that has been a key to his success.

Every necklace or pair of earrings starts with a sketch in his trusty Moleskine notebook. “I get juiced by drawing. If I get a moment when no one is in the house, I’ll go through old magazines, old drawings, some ideas that are still gestating, and I’ll wonder, ‘Is this right for this moment?”‘

Sybil is still very much his business partner, taking the title of chief marketing officer at the company. David is chairman and chief designer, and their son is also a company designer. The company added a CEO in 2006.

Yurman says he did a good job leading the hard-core business side, but deep down it’s just not his thing. (“Marketing is too big in this world, isn’t it?” he wonders aloud.)

He has other passions, though, including horses, cars, and humanitarian and charitable causes. In 2001, the David and Sybil Yurman Humanitarian & Arts Foundation was established, which supports Project ALS, the Elton John AIDS Foundation, YouthAIDS and Silver Shield Fund, a scholarship program for the children of police officers killed in the line of duty.

While he works in the fine jewelry arena, Yurman says it’s important to him to offer a range of prices. Make no mistake, his pieces aren’t cheap — you’ll spend hundreds of dollars, at least — but they’re not, he says, only for “the Gulfstream Jet set.”

“I think everyone should be able to participate in fine design. … Why can’t you design a beautiful bracelet and have affordability?”