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Magnetic orientation of four-ball test specimens and the effect on total test time



THE rolling contact four ball test is a standard way of assessing the performance of lubricants in rolling contact1. The test is well established and the effects of load and temperature on the results are well known2,3. However, the effect of the anisotropic fibre structure of the balls is often overlooked despite the work of Anderson and Carter4 and Scott5. Part of the reason for this oversight is because until now there has not been a nondestructive method for orientating the balls. We describe here a simple, nondestructive way of orientating the top ball of a four-ball test and we show how this can be used to reduce the time needed to rank different lubricants according to their effect on the fatigue life.

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  1. 1

    Institute of Petroleum Test Meth., IP 300/75T.

  2. 2

    Scott, D. Proc. Inst. mech. Engr Lond. 463–468 (1957).

  3. 3

    Scott, D. Proc. Inst. mech. Engr Lond. 183, 9–17 (1969).

  4. 4

    Anderson, W. J. & Carter, T. L. Trans. ASLE 2, 108–120 (1959).

  5. 5

    Scott, D. Proc. Inst. mech Engr Lond. 103–115 (1963).

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