Steel wire ropes — Determination of measured breaking force

Steel wire ropes — Determination of measured breaking force

1. In general, the test shall be carried out at an ambient temperature within the limits of 10 °C to 35 °C. In a strictly controlled test, the test temperature shall be maintained at 23 °C ± 5 °C.

2. Place the test piece on the test machine, ensure the centre axis of the test piece is in alignment with the centreline of the grips on the test machine.

3. For tensile pieces treated with the molten metal or resin socketing method, when a vertical machine is used, one end of the test piece should be held in the upper jaw, then set the force-measuring system to zero before attaching the lower fitting.

4. For the direct gripping method, a proper fixture should be chosen. Aluminium foil with carborundum can be used,if necessary, between the test piece and the fixture to avoid damage of the test piece by the fixture.

5. During the test, effective measures should be taken to avoid the rotation of the rope pieces which will affect the test accuracy.

6. The test force should be applied steadily during the test. It may be applied quickly until it exceeds 80 % of the minimum breaking force, Fmin. After 80 % of Fmin has been achieved, the force shall be applied at a rate of not more than 0,5 % Fmin per second.

It is important to observe safety procedures in the tensile testing of wire rope for the operator of the machine, as well as for observers and the surroundings, asuncontained wires during testing can impact and penetrate objects at a great distance. Adequate safety shields placed directly around samples, as well as around the operator and observers, should be used as a minimum.

7. Properties such as elongation at a specified force, elongation at fracture, force at first wire breaking, etc. can also be monitored according to the requirements.

8. The test may be discounted in cases where the rope fracture occurs within a distance of six rope diameters



Normative references : ISO 3108