Tri Tech USA, a producer of advanced metalworking components for military and industrial applications, will invest $4 million to relocate its headquarters and manufacturing operation to Liberty, South Carolina, according to South Carolina economic development officials. The company will employ at least 40 people when it moves from its current location in Vermont upon completion of a 41,000-square-foot facility; the facility is expected to be completed in August. Tri Tech will produce mobile kitchens that are transported to front-line military units, as well as metal components for a variety of industries. "The decision to relocate our business was not an easy one," say Joe and Linda Bacigalupo, the company's owners. "Pickens County, Alliance Pickens, and the state of South Carolina worked very hard to win our commitment to move here. It is clear to us that the support will continue long after the move, and we look forward to supporting the local community to make this a `win-win' for everyone." Information about incentives was not released.