Around Boeing Co.’s vast aircraft manufacturing hub in Seattle, the great belt tightening has begun as the planemaker and its factory workers settle in for a labor dispute that will test the resolve of both sides.

The ongoing strike by the largest union representing Boeing employees has already cost the company more than $500 million after one week, and those costs are set to escalate.

The strike at Boeing by 33,000 members of the International Association of Machinists union, which reaches its seventh day today, has already cost the company and workers $572 million, according to an estimate from Anderson Economic Group.