Extremely sharp and uniform field-emitter arrays (FEAs) with low work function and environmentally resistant emitter materials, such as TiN and Au, have been fabricated by a transfer metal mold FEA fabrication method to realize highly efficient, highly reliable, and low-cost vacuum nanoelectronic devices and aerospace nanodevices for electric propulsion engines. The tip radii can be linearly controlled from 2.5 to 52.5 nm by changing the thickness of the emitter materials. For the first time, turn-on electric fields of the transfer metal mold FEAs have been controlled by changing tip radii. Control of turn-on field is one of requirements for realizing vacuum nanoelectronic devices, such as field-emission displays, aerospace devices, and so on. The transfer metal mold fabrication method is useful for controlling the turn-on fields and tip radii and conductive to changing emitter materials while maintaining sharp and uniform emitter shapes.