Alumina Ceramic makes lamp bases.
Press Release Summary:

Original Press Release:
New 502-1400-FF Alumina Ceramic Used To Produce Hi-Temp Lamp Bases
SUMMARY
Aremcolox 502-1400-FF, a new high density alumina ceramic fabricated by Aremco Products, Inc., is now used to produce injection molded high temperature lamp bases for the theatrical lighting industry.
FEATURES
Aremcolox 502-1400-FF is a fully sintered 96% alumina ceramic that provides outstanding mechanical, electrical and thermal properties. This material offers a compressive strength of 340 Kpsi, dielectric of 225 volts/mil, and temperature resistance to 3000 OF. Aremcolox 502-1400 is also extremely resistant to corrosion and wear.
Aremcolox 502-1400 parts are fabricated to close tolerances thru injection molding, isostatic pressing and machining processes. Lapped, polished and metallized surface finishes are also available.