Abstract: A screw conveyor (10) is disclosed for use in environments having a large range of temperature. The screw conveyor (10) includes a hollow shaft (12) having a number of aligned circular holes (18a, 18b) therein, with adjacent sets of holes being at right angles to each other. A stake (16) is slidably inserted in each set of holes (18a, 18b) for securing a helical flight (14a-e) to the shaft (12). Four stakes (16) are welded to the back (26) of each of the helical flights (14) along a helical line corresponding to the helical path defined by the flights (14). The slidable interaction of the stakes (16) with respect to the shaft (12) permits each flight (14) to move relative to the shaft (12) during expansion or contraction of the screw conveyor (10). The back peripheral edge (20) and front peripheral edge (22) of adjacent helical flights (14) are overlapping and movable with respect to each other to further accommodate the expansion and contraction of the screw conveyor (10).