In a method of making screws, rivets or similar objects from a metal wire (6) the wire (6) is moved through a stationary cropping bushing (14) forwardly to a movable cropping bushing (24) present in a receiving position, following which the movable cropping bushing (24) is moved away from the receiving position substantially transversely to the axial direction of the wire to release a blank from the wire (6). The movable cropping bushing (24, 25) is then moved together with the released blank (26) further on to a discharge position, in which a punch (27) is adapted to move the blank (26) partly into a die (16) and to compress the blank (26) sufficiently to pre-upset it by cold flowing in the region between the die (16) and the movable cropping bushing (25). In an apparatus of making screws, rivets or similar objects the movable cropping bushing (24, 25) is secured to a transport device (15), by means of which it can be moved from a receiving position opposite the stationary bushing (14) to a discharge position opposite a die (16) between said die and a punch (27), which is adapted to move the blank (26) partly into the die (16) and to compress the blank (26) sufficiently to pre-upset it by cold flowing in the region between the die (16) and the movable cropping bushing (25).

Containers of explosive liquids can be prevented from exploding by filling the containers with meshes made from metal foil which occupies a negligible fraction of the volume of the container although it must completely fill the container. In order to refill the containers, the rib mesh (1) must consist of sufficiently small, spherical bodies (24). The invention also deals with the production of these filling bodies (24) from aluminum strip expanded into a mesh. The aluminum strip is first passed through a calibration opening (4) which compacts it into a bar (2) of circular cross-section which is then compacted perpendicularly to its length and continuously transported in the longitudinal direction as it is being squeezed. The front piece of the bar is then detached and pressed in a mould with a hemispherical bottom (21) by a die with the same inner contour to form a spherical filling body.

A tri-metallic electrical contact consisting of a head wire piece and a base wire piece which abut to an intermediate piece at its opposite ends, is produced by cold press operations performed by first and second die and punch sets. The first die and punch set causes plastic deformation of approximately only a half part of the aligned wire pieces, while keeping another half part of these pieces not deformed. The second die and punch set imparts, subsequent to, and independently from, the cold press operation performed by the first die and punch set, plastic deformation to the other half part of the pieces, whereby the abutting surfaces of the three wires are prevented from sliding movements laterally relative to each other during the cold press operations, and whereby irregular or insufficient deformation of the wires due to the differences of yield points of the wires is prevented.

A corrosion-resistant, headed fastener, such as a nail for exterior applications, is made from a carbon steel wire pre-coated with a protective, metallic layer having corrosion-resistant properties, the protective, metallic layer being discontinuous at a region on a leading end of the pre-coated wire. After at least part of a protective, metallic cap having corrosion-resistant properties is disposed near the leading end of the pre-coated wire, at least part of the protective, metallic cap is welded to the leading end of the pre-coated wire so as to cover the region where the protective, metallic layer is discontinuous, by impact welding, as a fastener is formed from the pre-coated wire in such manner that the fastener is formed with a shank and with a head, which is formed by deformation of the leading end. The welded part of the protective, metallic cap provides the fastener with corrosion resistance at the region where the protective, metallic layer is discontinuous, and the protective, metallic layer provides the fastener with corrosion resistance elsewhere. The protective, metallic layer is made from chromium, nickel, zinc, aluminum, or an alloy comprising zinc and aluminum, preferably from zinc or such an alloy. The protective, metallic cap is made from chromium, nickel, zinc, aluminum, or an alloy comprising zinc and aluminum, preferably aluminum, which can be visually differentiated from zinc or such an alloy.

A tri-metallic electrical contact consisting of a head wire piece and a base wire piece which abut to an intermediate piece at its opposite ends, is produced by cold press operations performed by first and second die and punch sets. The first die and punch set causes plastic deformation of approximately only a half part of the aligned wire pieces, while keeping another half part of these pieces not deformed. The second die and punch set imparts, subsequent to, and independently from, the cold press operation performed by the first die and punch set, plastic deformation to the other half part of the pieces, whereby the abutting surfaces of the three wires are prevented from sliding movements laterally relative to each other during the cold press operations, and whereby irregular or insufficient deformation of the wires due to the differences of yield points of the wires is prevented.