An electrode (200; 220; 240; 260; 300) for a plasma arc torch, the plasma arc torch including a plasma chamber defined by the electrode (200; 220; 240; 260; 300) and a nozzle, the electrode (200; 220; 240; 260; 300) comprising: an electrode body (202; 244; 302) having a front face at a first end (206; 224; 320); an orifice in the front face of the electrode body (202; 244; 302); and an elongated emissive insert (228; 262; 314) made of a high thermionic emissivity material and located within the orifice, the insert (228; 262; 314) having a forward end (262; 320) and a rearward end (264; 316), wherein the forward end (262; 320) of the insert (228; 262; 314) is oriented toward the front face of the electrode body (202; 244; 302), characterized in that the insert (228; 262; 314) has an initial configuration and an operational configuration, the operational configuration being formed after a plurality of operations of the torch, the initial configuration of the insert (228; 262; 314) having the rearward end of the insert (228; 262; 314) located at a first distance from the front face, and the operational configuration of the insert (228; 262; 314) having the rearward end located at a second distance, wherein D1 is at least 0.6 mm greater than D2, and wherein: (i) the electrode body (202; 244; 302) is formed of a high purity copper containing at least 99.81% copper; (ii) the first end of the electrode body (202; 244; 302) is configured to retain the insert (228; 262; 314) by radial compression; (iii) the insert (228; 262; 314) is tapered, such that a diameter of the forward end (262; 320) of the insert (228; 262; 314) is less than a diameter of the rearward end (264; 316) of the insert (228; 262; 314) (iv) the insert and the electrode body are formed of material having different coefficients of thermal expansion; such that the insert is arranged to move in a controlled manner in the bore of the electrode and the rearward end of the emitter advances toward the front face of the electrode during cutting cycles. an electrode body (202; 244; 302) having a front face at a first end (206; 224; 320); an orifice in the front face of the electrode body (202; 244; 302); and an elongated emissive insert (228; 262; 314) made of a high thermionic emissivity material and located within the orifice, the insert (228; 262; 314) having a forward end (262; 320) and a rearward end (264; 316), wherein the forward end (262; 320) of the insert (228; 262; 314) is oriented toward the front face of the electrode body (202; 244; 302), characterized in that the insert (228; 262; 314) has an initial configuration and an operational configuration, the operational configuration being formed after a plurality of operations of the torch, the initial configuration of the insert (228; 262; 314) having the rearward end of the insert (228; 262; 314) located at a first distance from the front face, and the operational configuration of the insert (228; 262; 314) having the rearward end located at a second distance, wherein D1 is at least 0.6 mm greater than D2, and wherein: (i) the electrode body (202; 244; 302) is formed of a high purity copper containing at least 99.81% copper; (ii) the first end of the electrode body (202; 244; 302) is configured to retain the insert (228; 262; 314) by radial compression; (iii) the insert (228; 262; 314) is tapered, such that a diameter of the forward end (262; 320) of the insert (228; 262; 314) is less than a diameter of the rearward end (264; 316) of the insert (228; 262; 314) (iv) the insert and the electrode body are formed of material having different coefficients of thermal expansion; (i) the electrode body (202; 244; 302) is formed of a high purity copper containing at least 99.81% copper; (ii) the first end of the electrode body (202; 244; 302) is configured to retain the insert (228; 262; 314) by radial compression; (iii) the insert (228; 262; 314) is tapered, such that a diameter of the forward end (262; 320) of the insert (228; 262; 314) is less than a diameter of the rearward end (264; 316) of the insert (228; 262; 314) (iv) the insert and the electrode body are formed of material having different coefficients of thermal expansion; such that the insert is arranged to move in a controlled manner in the bore of the electrode and the rearward end of the emitter advances toward the front face of the electrode during cutting cycles.