Hi

I have received a report with analysis results for a used grease sample. The results were all very fine (dropping point, penetration etc.) but I am a bit insecure about the Yield point. The Yield point has dropped from approximate 450 Pa to approximate 250 Pa. For me that look like a big drop, but according to the lab this drop is normal for greases and should not give any reason for concern.

Does anyone in this forum have any experience with Yield point and greases ?

I am very interested in a second opinion on this result.

I have a lot of experience with greases, however, never heard of yield point. What is the norm by which they have meassured the yield point?

If it is the pumping pressure, then it might not be relevant. but the number seem to be enormous to be that.

WHere is this grease applied and how? I am interested in learning more. Thanks.

The yield point is probably determined using a rheological device (Rheometer). The used parameters on this apparatus, the geometry and temperature are critical parameters. Are these known? A change from 450 to 250 Pa under the same testing conditions for the same product seems significant to me.