“The days of mass producing in New York City are gone,” Mr. Abel said. “If you were producing nuts and bolts by the tens of thousands 50 years ago, you’re not going to do it today. But creativity, or uniqueness or design is definitely something that can flourish in New York.”

Just as they have in many parts of the country, exports have taken up the slack for the business that Watermark lost during the economic downturn that began in 2008. The New York metropolitan area led the nation last year in exports, rising to $105 billion, its highest ever, from $85 billion in 2010, according to a report released last week by the International Trade Administration, a branch of the United States Department of Commerce that supports companies doing business overseas.

Fencing and flooring for dance clubs, stadiums, and big tents are being made in the Bronx by Signature Fencing and Flooring and shipped to South Africa, Japan, Britain and India. From Medford, on Long Island, Enecon, which makes corrosion-resistant coatings for industrial equipment, ships to 65 countries.

Manufacturing jobs in New York have declined by about 80 percent from a high of 1.1 million jobs in 1947, all but shutting down what had been a heavily trod avenue into the middle class for immigrants and people without advanced educations.