De Marssumermolen, Marssum 57 cogs. This drives the "wallower" (31 cogs) at the top of the "upright shaft". At the bottom of the "upright shaft" there are two "crown wheels"' The upper "crown wheel", which has 17 cogs drives an Archimedes' screw. The axle of the Archimedes' screw is diameter and long. This screw is used to pump water into the polder. The lower "crown wheel", which has 43 cogs, drives a gearwheel with 38 cogs on the axle of an Archimedes' screw, which is used to drain the polder. The axle of the screw is diameter and long. The screw is diameter.
Screw So, as a general rule, when buying a packet of "screws" nuts would not be expected to be included, but bolts are often sold with matching nuts. Part of the confusion over this is likely due to regional or dialectical differences. "Machinery's Handbook" describes the distinction as follows: This distinction is consistent with ASME B18.2.1 and some dictionary definitions for "screw" and "bolt". The issue of what is a screw and what is a bolt is not completely resolved with "Machinery's Handbook" distinction, however, because of confounding terms, the ambiguous nature of some parts of the distinction, and usage variations.