If a shaft having a continuous direction of rotation be given end play so that while rotating it may move endwise, the particles abraded are again kept separated, and the conditions of lubrication are such as to give a minimum of wear, because the formation of fine rings or serration is avoided, the end motion serving to cause the wear to smooth the surfaces.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose
The whole suture shows fairly good serration.
"A Bilateral Division of the Parietal Bone in a Chimpanzee; with a Special Reference to the Oblique Sutures in the Parietal Bulletin of the AMNH, Vol. XIII, Article XXI, pp. 281-295, Dec. 31, 1900"
Ales Hrdlicka
The coronal suture on this side, below the division, shows serration about equal to that of the abnormal suture; the obliterated portion above this was, so far as can be seen, more simple.
"A Bilateral Division of the Parietal Bone in a Chimpanzee; with a Special Reference to the Oblique Sutures in the Parietal Bulletin of the AMNH, Vol. XIII, Article XXI, pp. 281-295, Dec. 31, 1900"
Ales Hrdlicka