PMI was over the 50-point threshold that signals expansion in the manufacturing sector for the fourth month in a row.
The new orders index rose in January from the previous month and remained over 50.
The production volume index fell, but stayed over the 50-point mark.
The employment index showed an expansion, after falling under the 50-point threshold in the previous month.
Delivery times were longer than in December.
Purchased inventories rose "at a strong pace" after a "moderate" decline in the previous month.