Summary Box: A look at the Machinists union at Boeing

WHO THEY ARE: 27,000 Boeing commercial airplane employees are members of the International Association of Machinists and Aerospace Workers.

WHERE THEY WORK: 24,500 in the Puget Sound, Wash.-area; others in Wichita, Kan., Portland, Ore., and Southern California.

WHAT THEY DO: 400 different jobs, from machinists who make plane parts, assembly mechanics and tool-and-die makers to store keepers, registered nurses and people who paint planes.

HOW MUCH THEY MAKE: $58,000 a year, on average.

WHAT THEY'LL BE TALKING ABOUT: Key points of contention include Boeing's proposals for higher health care payments, raises at the low end of the pay scale but not at the top, ending the pension plan for new hires and separating Wichita-based workers from the contract.