Manufacturing is slowing down
Economists had estimated a Purchasing Manager's Index flash reading of 53.8 in August, unchanged from the prior period.
Manufacturing output growth slowed from a three-month high in July, weighing down the index. New orders and employment also grew at a slower pace.
"August's survey highlights a lack of growth momentum and continued weak price pressures across the U.S. manufacturing sector, which adds some fuel to the dovish argument as policymakers weigh up tightening policy in September," wrote Markit senior economist Tim Moore.
"With the headline PMI swiftly losing ground after a modest rebound during July, the latest figure now points to the weakest overall pace of manufacturing growth for almost two years."
Earlier this week, the Empire State manufacturing survey index fell to the lowest level since 2009, and the Philadelphia Fed's manufacturing index was stronger than expected.