TECHALLOY GLASSEAL 29-17 is an iron-nickel-cobalt alloy with a thermal expansion rate that is unlike most metals and closely matches the thermal expansion characteristics of borosilicate glass, PYREX glass, and other similar low-expansion materials. It assures precisely controlled expansion properties that are ideal for usage in glass-to-metal seals. Typical applications are transmitting tubes, relays and electronic power tube envelopes. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-60. Producer or source: Techalloy Company Inc..