loose ring of surrounding rock
base-ring and frame-ring
collector ring (slip-ring)
column-ring beam joint with shear ring bars
outside ring in-feed system ring
ring of n×n matrices over ring R
ring out the old year and ring in the new
Riser-ring and Ring Module
short-proof ring (arcing ring)
the Western Ring Road Sector of Central Ring Road
anal ring hairs anal ring setae
ratio of erosion thickness and stratigraphic thickness
thickness difference to average thickness
Thickness-control with thickness gauge
tube thickness (=tube-wall thickness)