Patent ID: 8101882

Claim:
An electrode for a plasma arc torch, the electrode comprising: an electrode body formed of a high thermal conductivity material, the electrode body including a first end and a second end defining a longitudinal axis; a bore defined by and disposed in the first end of the electrode body, the bore including a closed end and an open end, the bore defining at least a first and a second dimension each transverse to the longitudinal axis, the second dimension being closer to the closed end of the bore than the first dimension; and an insert formed of a high thermionic emissivity material disposed in the bore, the insert including an exterior end disposed near the open end of the bore and a contact end disposed near the closed end of the bore, the insert defining at least a first and a second dimension each transverse to the longitudinal axis, the second dimension being closer to the closed end of the bore than the first dimension, wherein the second dimension corresponds to an annular notch; wherein at least one of the second dimension of the bore is greater than the first dimension of the bore, or the second dimension of the insert is greater than the first dimension of the insert.