Patent ID: 7204738

Claim:
A method of forming a metal halide discharge tube comprising: arranging a tubular body in an essentially vertical orientation; disposing a first loose-fit T-plug having a stem portion, a cylindrical portion and an annular flange in an upper open end of the tubular body so that the cylindrical portion of the first loose-fit T-plug is disposed within the open end of the tubular body in a contact-free, spaced relation with an inner wall of the tubular body and with the annular flange seating against an annular top end edge surface of the tubular body; and firing the tubular body and the first loose-fit T-plug to shrink fit the tubular body and the loose-fit T-plug to interfuse the loose-fit T-plug with the upper end of the tubular body in a manner which results in a monolithic body, wherein said firing comprises rapidly raising the temperature of the tubular body and the loose-fit T-plug at a rate of greater than 500.degree. C./minute.