An electrical machine comprising: a teeth component (102;202) defining a plurality of circumferentially spaced slots between teeth; and a radially inner layered conductor wound into the slots, wherein the radially inner layered conductor includes a plurality of conductive layers (110, 112, 114) wherein at least two adjacent layers in the plurality of conductive layers have electrical conductivities that are different from one another; and characterised in that an interface (116, 118) is formed between each pair of adjacent layers of the at least two adjacent layers that is tangentially aligned with a circumferential direction around the teeth component and extends from an insulator on one side of the radially inner layered conductor to an insulator on the other side of the radially inner layered conductor; wherein the at least two adjacent layers include a radially inner layer of a relatively high electrical conductivity material, a middle layer of a relatively low electrical conductivity material, and a radially outer layer of a relatively high electrical conductivity material; wherein each pair of adjacent layers of the at least two adjacent layers are in electrical communication with one another with no intervening insulator therebetween; the electrical machine further comprising a radially outer layered conductor wound in each slot of the teeth component (102; 202) outboard of the radially inner layered conductor, wherein the radially outer layered conductor includes a plurality of layers wherein at least two adjacent layers in the plurality of layers have electrical conductivities that are different from one another; and wherein the radially inner and radially outer layered conductors are separated from one another and from the teeth by an insulator. a teeth component (102;202) defining a plurality of circumferentially spaced slots between teeth; and a radially inner layered conductor wound into the slots, wherein the radially inner layered conductor includes a plurality of conductive layers (110, 112, 114) wherein at least two adjacent layers in the plurality of conductive layers have electrical conductivities that are different from one another; and characterised in that an interface (116, 118) is formed between each pair of adjacent layers of the at least two adjacent layers that is tangentially aligned with a circumferential direction around the teeth component and extends from an insulator on one side of the radially inner layered conductor to an insulator on the other side of the radially inner layered conductor; wherein the at least two adjacent layers include a radially inner layer of a relatively high electrical conductivity material, a middle layer of a relatively low electrical conductivity material, and a radially outer layer of a relatively high electrical conductivity material; wherein each pair of adjacent layers of the at least two adjacent layers are in electrical communication with one another with no intervening insulator therebetween; the electrical machine further comprising a radially outer layered conductor wound in each slot of the teeth component (102; 202) outboard of the radially inner layered conductor, wherein the radially outer layered conductor includes a plurality of layers wherein at least two adjacent layers in the plurality of layers have electrical conductivities that are different from one another; and wherein the radially inner and radially outer layered conductors are separated from one another and from the teeth by an insulator.