gmmco

Stephen Junkunc II founded GMMCO in 1918, realizing a dream of owning his own machine shop. Stephen progressed into manufacturing metal stampings for casket hardware. With the outbreak of World War II, GMMCO converted the shop for the war effort and began manufacturing various aircraft parts, including B-29 hydraulic spools on behalf of Ford Motor Company, who was sub-contracting work from engine maker Pratt & Whitney.

GMMCO’s quality and service was so dependable that Pratt & Whitney asked GMMCO to manufacture a critical fuel nozzle seal for JT3 turbofan and J57 turbojet – the world’s first jet engine to develop 10,000 lbs. of thrust and the power-plant for the B-52 Stratofortress.

Since then, GMMCO went on to design many other types of unique fuel nozzle seals for Pratt & Whitney, including our signature “knife-edge seal”. Many years and millions of seals later, GMMCO seals and related parts are being used on many military, commercial, and aero-derivative turbine engines. GMMCO is now under the leadership of Erik Junkunc, fourth generation of the Junkunc family.

At GMMCO, we pride ourselves on meeting our clients’ diverse machining needs. With our 5-axis Star CNC Swiss machine, we can accommodate stock from 0.050″ to 1.25″ in diameter, up to 6″ in length, and can handle up to 12 features on a single part. Our arrays of machining processes are appropriate for applications such as connectors, fasteners and fittings, and we feature a maximum production volume of 10,000 units per run. And to ensure each project meets our high standards, we offer a full optical comparator, as well as CMM inspection capabilities. For more information about our CNC Swiss machining services, please contact GMMCO.

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2634 N. Keeler Avenue
Chicago, IL 60639
Phone: 1.773.235.3700
Email: sales@gmmco.com