A stator assembly comprises an annular platform (1) defining a boundary of an annulus and a plurality of guide vanes (2) for arranging in a circumferential array on the annular platform (1). The platform (1) includes a circumferential array of slots each slot having, at a first end, walls converging (3) from an annulus facing side towards an opposite side of the platform and then extending parallel (4) towards a second end. One or more cooling holes (5) is arranged in a wall (3,4) of the slot. Each vane (2) includes a root portion (7) which converges in a first region (8) distal to the root end and then extends parallel towards the root end in a second region (9). The root portion (7) is configured to engage in a slot of the platform (1) with the first region (8) abutting a convergent wall portion (3) of the slot and the second region (9) spaced from a parallel wall (4) of the slot. At least one bore (11a, 12a) is provided in a parallel wall (4) of each slot and at least one bore (11b, 12b) is also provided in the second region of the root portion (7). The bores (11a, 11b; 12a, 12b) in the two components are positioned to align when a vane (2) is engaged in a slot. The aligning bores (11a, 11b; 12a, 12b) together are configured to receive a pin (13) for mechanically securing the vane in the slot. A braze joint (14) may be added between the root portion (7) and parallel slot walls 4.