Abstract: A thyristor housing and method of its manufacture in which a gate tube passing through a radially directed bore in a tubular insulator is hermetically sealed by metal closures at each end to prevent accumulation of contaminants inside the gate tube during final plating the metal parts secured to said housing. The metal closure on the inwardly directed end of the gate tube is frangible for receiving a lead from the thyristor to be packaged in the housing.