Of the industry subgroups, oil, coal and chemicals led the way at 54 after returning to expansion.
Metal product manufacturing managed to keep its head above water at 50.8, after dropping 5.1 points from June.
Business NZ's executive director for manufacturing, Catherine Beard, said the result to a large degree mirrored what was occurring overseas.
"While the current New Zealand result represents a minor fall into contraction, spare a thought for the Australian manufacturing scene - that fell significantly in July to 40.3," she said.
"Their low result is partly symptomatic of high current costs within their sector."
Globally, the JPMorgan global manufacturing PMI contracted further in July to 48.4.