An expanded metal produced by repeated penetration of a movable cutting die including teeth into a metal sheet that is run through an expansion device in a feed direction, the expanded metal including a plurality of loops, wherein the loops include bars that envelop loop openings and that are connected in nodes, wherein each of the loops includes a loop opening length measured in the feed direction along a line from a node center to node another center of two nodes that are arranged behind one another in the feed direction, wherein each of the loops includes a loop opening width that is measured transversal to the feed direction along a line from a node center to a node center of two nodes that are arranged adjacent to each other transversal to the feed direction.

An expanded metal produced by repeated penetration of a movable cutting die including teeth into a metal sheet that is run through an expansion device in a feed direction, the expanded metal including a plurality of loops, wherein the loops include bars that envelop loop openings and that are connected in nodes, wherein each of the loops includes a loop opening length measured in the feed direction along a line from a node center to node another center of two nodes that are arranged behind one another in the feed direction, wherein each of the loops includes a loop opening width that is measured transversal to the feed direction along a line from a node center to a node center of two nodes that are arranged adjacent to each other transversal to the feed direction

A first roll (20) and a second roll (40) of a roll forming device are provided with a plurality of stacked cutting blades (22, 122) and retainers (21, 121). The retainers (21, 121) pass through the stacked cutting blades (22, 122) and receive a first rotating shaft (16) and a second rotating shaft (18). Projections (21a, 121a) are formed on end portions of the retainers (21, 121). When the cutting blades (22, 122) are stacked, the projections (21a, 121a) control positioning operation of the cutting blades (22, 122). With this constitution, when the cutting blades (22, 122) are joined in a stacked state to the retainers (21, 121), the cutting blades (22, 122) in the stacking direction is controlled with the retainers (21, 121).