Manufacturing firms are squeezing the more hours ever out of their employees than at any time since World War II.

For Barclays' Cooper Howes, that means more hiring is around the corner for a sector that hasn't seen a whole lot of since the Great Recession.

The average hourly workweek in manufacturing now averages 42, most since 1945. Chart:

In a recent note, Howes says hours probably can't go much higher. Meanwhile, manufacturing productivity gains have also topped out, at about 2%. And max hours plus max productivity, he says, means "...employers will be forced to hire in order for output to keep up with increasing demand."

It's badly needed.

Over the past few years, manufacturing has seen the third-lowest jobs recovery among four major sectors of the economy. Only construction has had it worse:

It's also been extremely noisy, averaging about 6,000 monthly new payrolls added over the past 12 months.

But Howes says 2014 should see an average of 20,000 new payrolls added per month. And it seems to have already begun, as the general uptick since July shows.

Howes:

"...'soft' activity indicators, such as manufacturing surveys, and 'hard' indicators such as industrial production and the length of the average workweek, point to a recent pickup in hiring for the sector. We expect this to continue, driven largely by increased demand from the ongoing recoveries in the housing and auto sectors."

Good news for a sector which, despite looking strong on paper, hasn't been letting very many new faces through its gates.