the described point of tangency the point of tangency between the flat and crowned surfaces of friction surface 30 should be at or below the point of intersection of the centerline of spring 24 with surface 30 if the point of tangency is above the intersection of the spring centerline there may be the described clearance between the bottom portion of vertical friction surface 40 and the column wear plate thus leading to uneven wear the particular described slanted surface of the wedge will redistribute both friction and wear over a larger area of the bolster pocket and will substantially eliminate the problem of having excessive wear and force applied to the top of the wedge and to the top of the bolster pocket in addition the described construction will permit larger longitudinal impacts to the car body with less tendency to have the bolster rotate about its lateral axis with respect to the side frames this in turn will reduce the stress on the fore and aft portions of the bolster centerplate rim one of the problems associated with excessive wear at the top of the friction wedge and the top of the bolster is that it has in the past permitted excessive rotation of the bolster relative to the side frames which in turn has a tendency to wear the front and rear portions of the bolster center plate rim by substantially reducing or eliminating rotation of the bolster wear on the center plate.