The survey results, released Monday, show that manufacturing activity in San Bernardino and Riverside counties has been on the rise throughout the first quarter of 2012.
What's more, manufacturers who responded to a Cal State San Bernardino survey reported that March was a particularly healthy month for their businesses.
Last month's robust pace of business followed moderate growth over the previous two months, not to mention a sluggish end to 2011 when Inland Empire manufacturing was on the verge of contracting.
"It (growth) is sustained in the sense that it's going on at a weak rate of growth, but all the signals are increasing," said Shel Bockman, of the San Bernardino campus' Institute of Applied Research and a co-author of the Inland Empire Report on Business.
Bockman became more enthusiastic over the course of a telephone interview, noting that local manufacturers' views seem to mirror increasing optimism in other parts of the country and saying Monday's data is "one of the best reports ever" in the history of the campus' manufacturing survey.
The Institute for Applied Research surveys purchasing managers at roughly 30 San Bernardino and Riverside county manufacturing firms for its monthly survey.
Researchers take managers' responses to calculate a Purchasing Manager's Index for the two-county area. Any number above 50 signifies growth, and in March, the index jumped from 53.5 to 60.8.
Also in March, the survey's hiring index, reached 63, its highest point since May 2005.
The index cannot be used to generate numbers on how many people have actually been hired, but analysis from Los Angeles-based Beacon Economics shows San Bernardino and Riverside county manufacturers hired roughly 2,200 people from November to February.
"I would say as of November, things really started making a turn for the better," said Derek Dennis, president of Solar Atmospheres California. "Every month seems to be getting better and better."
Solar Atmospheres has a plant in Fontana where metal components for aircraft and other applications are subjected to heat treatments.
The company has a dozen employees at its Fontana plant and Dennis said the plans are to expand to 45 workers - enough to run the plant seven days a week.
Solar Atmospheres is not counted in the Cal State San Bernardino survey, but Rancho Cucamonga-based aircraft parts maker PneuDraulics is included in the report.
PneuDraulics' materials director Terry Herrmann also said the pace of business at his company has increased in recent months.
"We've continued to hire since the middle of last year," Herrmann said.
PneuDraulics has about 230 employees and has hired about 25 people in the past several months.
In March, the Inland Empire's manufacturing sector grew at a higher pace than that of the United States overall. The local figure of 60.8 compares with a national index of 53.4, according to the Institute for Supply Management.
A big difference between Inland Empire and national trends, however, is that whereas local manufacturers have reported three months of expansion, national manufacturers have reported 32 straight months of growth.
Contact Andrew via email, by phone at 909-386-3872 or 909-483-8550, or on Twitter @InlandBizz.