After the grain has been threshed with the flail and the grain straw has been removed, grains, chaff, clods, short straw, stones and other impurities remain together. Some of the impurities are removed with the help of the grain sieve. By shaking the sieve back and forth, the grains fall through, leaving chaff and short straw behind. The grain sieve is also used to separate chaff from dust / sand (1).
The flax worker also uses a grain sieve to separate the linseed from the chaff after threshing (see bruising mail).
The grain sieve is a large (diam. 50-100 cm) round sieve (2) with 2-3 wooden rings (height approx. 10-20 cm) between which a flat perforated bottom of metal (zinc) or leather (3) is clamped. In the latter the small round or elongated holes (diam. 1-2 mm; center distance approx. 4 mm) (4) are punched with a punch. The center of the sieve bottom is often decorated with a figure, a date, initials and / or place name.
Sometimes 1, 3 or 4 holes or slots are provided in the edge to hang the screen from ropes or straps respectively, which meet at a height of about 90 cm and are attached with a hook to the rafters of the roof of the shed. The purpose of this is to make the slightly inclined sieve easier to move and shake.
To be distinguished from the winnow fan which sorts by weight.
See also the drum sieve. [MOT]