Main concave threshing drum. combine harvester Claas - 1312х610 mm one-section, perforated, welded construction, is part of the threshing and separating device of body of the harvester.
For the models of combine harvesters CLAAS/Claas:
| Type | Perforated |
| the cell Size, mm | 19 x 40 |
| Length mm | 1312 |
| Width, mm | 610 |
| part number | 663347, 777551, 000663347, 000777551 |
Intended in the process of threshing (hitting the concave strips) to highlight of straw much of the grain together with sexual strasnoy on the Board, sieve mill.