Abstract: A stator core for an electrical machine includes an annular yoke and a plurality of teeth spaced circumferentially on the annular yoke and extending radially therefrom, the spaces between the teeth defining circumferentially spaced winding slots. The teeth are formed as separate components from a soft magnetic powder material. Each tooth has non-decreasing cross-sectional dimensions in a direction towards a distal tip along a length of the tooth corresponding to a winding slot, and has the same or smaller cross-sectional dimensions along a proximal end of the tooth. Thereby, the tooth may be assembled with a core-back section of the annular yoke and is able to receive a coil before the assembling with the yoke.

Abstract: A method of forming a closed-end vessel by backward extrusion comprises providing an extrusion billet having a front surface with an axial recess and a body of an extrudable material positioned in the recess. Backward extrusion results in the formation of a closed-ended vessel, for example a pressurized gas cylinder, composed of the material of the extrusion billet with a weld bonded inner surface lining of the extrudable material.