Japanese etymology of ‘Hama’ meant to “Between” (as the stuff between object and floor in kiln) or also meant to “Beach” (as its flatness).
Very solid as well used over and over and over in the kiln for the long years, as a potter’s tool which was applied to a conceptional tea utensil (of ‘cha-no-yu’) as an art form of ‘mitate’ in the later years. Edo period at least or earlier. approx. 16.0 x 15.5 x 1.5cm (6.29 x 6.10 x 0.59in)