Testing of Wires and Cables

All metals can be formed into wire, which is a very common metal product. Wires are used in all areas of the manufacturing industry: in construction engineering, in electrical technology and energy technology, in aircraft and automobile manufacture, and in medical technology. Wire braided into cables is used in load-bearing applications in cable railways, elevators, cranes, bridge-building, anchorings, and fastenings. This wide range of applications means that mechanical demands are extremely varied and that testing material properties is often highly relevant to safety.
In addition to a fork head for connecting the customer's cable attachments, hydraulic grips in a separate second test area are used to grip the specimen. This makes it possible to test normal round specimens—an additional tensile testing machine is not needed for round materials. The testXpert II testing software helps users set up and perform tests, and evaluate test results. 

Hardness Testing

Hardness testing of wires is not only performed on the surface, but also in the wire core. For hardness testing of the core, grindings of the wire cross-section are made and the hardness values are determined primarily to Vickers (DIN EN ISO 6507-1). Wires are rolled and wires with smaller diameters are pulled. The material undergoes cold hardening and a change in the grain geometry. Elongated metallographic constituents develop in cold-drawn wire, which can be efficiently tested to Knoop (DIN EN ISO 4545-1). The hardness testing methods used here are performed using ZwickRoell's hardness testers for low-load Vickers hardness testing and micro Vickers hardness testing.

Rotating Bar Bending Fatigue Tests

In many applications, wires are subjected to various cyclic stresses. Fatigue strength can be determined quickly and easily in rotating bar bending fatigue tests in which the rapidly rotating (up to 6000 rpm) specimen is additionally loaded with a force perpendicular to the axis of rotation. This flexure plus rotation provides a tensile-compression loading of the specimen surface. Specimen preparation is especially important here, an undamaged surface being essential.

Tensile tests at 3,000kN - ZwickRoell modernizes testing machine for steel wire ropes at Redaelli

At its factory in Gardone val Trompia, Italy, Radaelli produces steel wire ropes for a wide range of uses. These include offshore applications, construction machinery, ropeways and cableways and bridge-building. The growing demand for wire ropes with ever-higher load capacity is also placing an increasing burden on quality assurance. After modernization by ZwickRoell the testing machine can now perform tensile tests up to 3,000kN.