HTH Companies Inc Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, Ohio, Oklahoma, South Dakota, Tennessee, Wisconsin, Mechanical Insulation, Scaffold Erection, Scaffold Rental, Millwright, Pipefitting, General Construction, Hydro blasting, Industrial cleaning, Vacuum Truck Services, Industrial Maintenance, Heat trace, Removable insulation blankets, Confined space, Janitorial, Electrical, Piping layout, Ethanol, Grain Processing, Chemical Manufacturing, Refineries, Industrial Maintenance, Commercial, Hoberock The Leading Professional Industrial Service Provider in the Industry Since 1984. hth companies continues to promote the merit shop philosophy it was founded upon: …