SEATTLE >> Blue-collar workers from Boeing walked picket lines in the Pacific Northwest instead of building airplanes on Friday after they overwhelmingly rejected a proposed contract that would have raised their wages by 25% over four years.

The strike by 33,000 machinists will not disrupt airline flights anytime soon, but it is expected to shut down production of Boeing’s best-selling jetliners, marking yet another setback for a company already dealing with billions of dollars in financial losses and a damaged reputation.

The company said it was taking steps to conserve cash while its CEO looks for ways to come up with a contract that the unionized factory workers will accept.

Boeing stock fell more than 3% in afternoon trading, bringing its decline for the year to nearly 40%.

The strike started soon after a regional branch of the International Association of Machinists and Aerospace Workers reported that in a Thursday vote, 94.6% of participating members rejected a contract offer that the union’s own bargaining committee had endorsed, and 96% voted to strike.

Shortly after midnight, striking workers stood outside the Boeing factory in Renton, Washington, with signs reading, “Historic contract my ass” and “Have you seen the damn housing prices?”

Car horns honked and a boom box played songs including Twisted Sister’s “We’re Not Gonna Take It” and Taylor Swift’s “Look What You Made Me Do.”

Many of the workers who spoke to reporters said they considered the wage offer inadequate given how much the cost of living has increase in the Pacific Northwest. John Olson said his pay has increased just 2% during his six years at Boeing.

“The last contract we negotiated was 16 years ago, and the company is basing the wage increases off of wages from 16 years ago,” the 45-year-old toolmaker said. “They don’t even keep up with the cost of inflation.”

Others said they were unhappy about the company’s decision to change the criteria used to calculate annual bonuses.

The machinists make $75,608 per year on average, not counting overtime, and that would have risen to $106,350 by the end of the proposed four-year contract, according to Boeing.

Under the rejected contract, workers would have received $3,000 lump sum payments and a reduced share of health care costs in addition to pay raises.

Boeing also met a key union demand by promising to build its next new plane in Washington state.

However, the offer fell short of the union’s initial demand for pay raises of 40% over three years.

The union also wanted to restore traditional pensions that were axed a decade ago but settled for an increase in new Boeing contributions to employee 401(k) retirement accounts of up to $4,160 per worker.

The striking machinists assemble the 737 Max, Boeing’s best-selling airliner, along with the 777 jet and the 767 cargo plane.

The walkout likely will not stop production of Boeing 787 Dreamliners, which are built by nonunion workers in South Carolina.