- Allied Mechanical Services, Inc. is one of southwest Michigan's largest full service Mechanical Contracting firms, with offices located in Kalamazoo, Jackson, and Hudsonville. We are a licensed mechanical contractor specializing in commercial and industrial Process Piping, Plumbing, HVAC and Custom Sheet Metal Fabrication. In addition, we also maintain a Mechanical/Electrical design firm, ...www.alliedmechanical.com