American manufacturing companies grew faster in August as the industrial sector continues to lead the recovery, and managers’ desire to hire shot up to the highest level in nearly 30 years.

The Institute for Supply Management said yesterday its manufacturing index rose to 56.3 in August from 55.5 in July. A reading above 50 indicates growth. The manufacturing sector has expanded for 13 straight months.

Economists polled by Thomson Reuters had forecast a weaker reading of 53.0.

Rising exports overseas and demand from businesses for capital equipment and supplies have helped propel production in factories for a year.

Momentum had slowed earlier this summer from a reading of 60.4 in April, which was a six-year high. But employers are still eager to add jobs.