Detroit Diamond Drilling has been around since 1961. It all started with Roy Sweet, who founded the company after leaving his job at Ford Plant 2 where they made cars for Canada and other countries in World War II." Detroit's oldest Stihl dealer is also here because of these two men - Jim Grunewald & Kirt Hardoin joined DDT right outta high school when it was just another small concrete drilling firm catering mostly towards farmers...