An index value above 50 shows expansion in the manufacturing sector, while a value under 50 signals contraction.
Among the sub-indices that comprise the PMI, the new orders index and the production volume index both fell under the 50-point mark.
The employment index also dropped and was under 50.
Delivery times were longer than in February.
Purchased inventories were down for the second month in a row after expanding for a period of 37 months.