Reducer shaft from Ø25.4mm (1 inch) to Hexa SW25 for Crawford doors with hexagonal shafts. In mid-2006, Crawford adjusted the wall thickness of the hexagonal shaft to 3.5mm (was 2.5mm). As a result, the internal hexagon dimension changed from 27mm to 25mm. The reducer shaft SW25 is usually required for a Crawford door built after 2006.