Abstract: An incandescent lamp assembly has a generally elliptical vitreous envelope including a cylindrical neck, stem mount with a pair of lead-in wires, and a screw-in base capped on the cylindrical portion of the envelope. The cylindrical neck of the envelope has a circular protruded ring along the entire periphery thereof and in the corresponding position of the screw-in base is provided a concave channel, for a push-in coupling. A flared rim is integrally formed with the concave channel and extends gradually outwardly to bear along the envelope, giving elastic deformation to the upper half of the screw-in base. The lead-in wire is interposed between the cylindrical neck and the screw-in base and fixedly positioned at the circular protruded ring. For prevention of relative rotational movement, heat resistant silicone rubber is applied on the circular protruded ring.