The mechanical behaviour of steel cords changes considerably when the cords are embedded completely into rubber and cured. Particular changes can be observed for the breaking strength, the elongation ability and the flexibility Whereas any kind of rubberizing leads to a decrease of the cord flexibility the breaking strength will increase at the same time. This increase depends on the selection of the steel and on steel processing, cord construction and type and extend oi rubber penetration. The examination was done with steel cords for conveyor belts of the tensile class St 1600 and St 2500 in nonrubberized and rubberized condition. For. every tensile class, two cord constructions with three variations of the strand spacing were examined. On account of the rubberizing the breaking strength increases whereas the elastic elongation is reduced The influence on the pull-out force is negligible.