The fluting looks ruff in the races but will control low RPM without heat problems. They don't hold load pressure perpendicular to the shaft they are primarily thrust control. Can't beat the price for it's intended use. Ruff fluting is to prevent bearing skid when the bearings get dirty and loose also a thrust bearing must have very little contact area with the race or it will destroy itself. If it is A high speed heavy load you may want to look further for a smooth seat hi pressure bearing. I am sure you will have to pay more for those.