Center Column
AssemblyVertical steel tube on which every tread is threaded; it carries the full stair load down to the base plate and is the datum for the whole geometry. A full specification article for this item is being written. Meanwhile its bill of materials and connections are below.
Bill of materials for Center Column
5 top-level lines as of r162330| # | Item / sub-assembly | Part no. | Qty/assy | Ext. qty | Parts | Type |
|---|---|---|---|---|---|---|
| 1 | Column Tube | spiral-staircase-column-tube | 1× | 1 | · | part |
| 2 | Column Extension Sleeve | spiral-staircase-column-sleeve | 1× | 1 | · | part |
| 3 | Column Cap | spiral-staircase-column-cap | 1× | 1 | · | part |
| 4 | Clamp Collar | spiral-staircase-clamp-collar | 2× | 2 | · | part |
| 5 | Fastener Set | fastener-set | 1× | 1 | · | part |