Abbott-Firestone curve

The Abbott-Firestone curve or bearing area curve (BAC) describes the surface texture of an object.

The curve can be found from a profile trace by drawing lines parallel to the datum and measuring the fraction of the line which lies within the profile.

[1] Mathematically it is the cumulative probability density function of the surface profile's height and can be calculated by integrating the probability density function.

[2] The Abbott-Firestone curve was first described by Ernest James Abbott and Floyd Firestone in 1933.

[3][4] It is useful for understanding the properties of sealing and bearing surfaces.