U.S. manufacturers expanded at a faster pace last month, another sign of strength for American industry.

The Institute for Supply Management, a trade group of purchasing managers, reports that its manufacturing index rose to 58.7 in May from 57.3 in April. Anything above 50 signals growth. American manufacturing is enjoying a 21-month winning streak.

New orders, production and hiring all grew faster. Export orders grew more slowly than they did in April.

Sixteen of 18 manufacturing industries expanded, led by textile mills and producers nonmetallic minerals.

Factories are benefiting from healthy economic growth in the United States and around the world.

In another sign of strength, the Labor Department says that employers added 223,000 jobs in May and the unemployment rate fell to an 18-year low of 3.8 percent.