Friction Coefficient - steel on hardened steel
Friction Coefficient - steel on hardened steel
(OP)
I was wondering if someone could give me an approximate value for the coefficient of friction between two steel parts rubbing against each other. The first steel part is made of SAE 4140 and is not treated. The second steel part is made of hardened steel. If anyone has a value or knows where I could find it, it would be most appreciated.
Thanks
Tom
Thanks
Tom





RE: Friction Coefficient - steel on hardened steel
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Friction Coefficient - steel on hardened steel
RE: Friction Coefficient - steel on hardened steel
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Friction Coefficient - steel on hardened steel
I looked in Marks' Standard Handbook for Mechanical Engineers 10th edition for their friction data. Table 3.2.4 shows the data you referenced: hard steel on hard steel is 0.78, while mild steel on mild steel is 0.74. These data are attributed to Campbell, Trans. ASME, 1939. Two pages before Table 3.2.4 is Table 3.2.1. It shows static friction coefficients for steel on steel. In the "Grease-free in vacuum" condition, it lists a value of 0.78. In the "Grease-free in air" condition, it lists 0.39. These data are attributed to the same source as before: Campbell, Trans. ASME, 1939.
Friction is a complex subject, with huge variability. One must be careful when relying upon it to perform a function. Calculations cannot use a single value from a source that did not have the same conditions. In fact, it is difficult to obtain the same conditions, so each case should be tested to have confidence in the values.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Friction Coefficient - steel on hardened steel
RE: Friction Coefficient - steel on hardened steel
RE: Friction Coefficient - steel on hardened steel
Rothbart: Mechanical Design and Systems Handbook
1964 McGRAW-HILL
Section 11: FRICTION. LUBRICATION AND WEAR
(f) Kinetic Friction of Metals.
Also see: Dubbel's Handbook (Originally German, but also in English.)
Dubbel (1966)indicates all over much lower values.
Or has there been a development towards more agreement later?