PTC Instruments

ARBOR FENCE INC CHAPARRAL STEEL CO., INC. METALBOSS TECHNOLOGIES INC. KNOLL INC. BERKEY MACHINE CORP MICHIGAN SHIPPERS SUPPLY INC ELKEM CARBON SAFETY TEST & EQUIPMENT COMPANY, INC. TRINITY INDUSTRIES INC HI-TECH ENGINEERING INC

SCA TISSUE NORTH AMERICA LLC FORT WAYNE METALS RESEARCH GLASGOW MANUFACTURING BLACKHAWK STEEL CORP ERICKSON, B., MANUFACTURING LTD. TIME FASTENER CO INC GENERAL METALWORKS CORP CRAFT INDUSTRIES INC COMTECH SYSTEMS INC WENZEL METAL SPINNING INC