identify your lightbulb > bulb identification key


This is an inside frosted light bulb.  Inside frosted light bulbs were introduced in 1925 and replaced the older method of outside frosting.  The inside surface of this bulb is entirely frosted, with a smooth surface on the outside of the bulb, giving the bulb a pearl-like color appearance. (Click here to learn more about the development of inside frosting.)  Single-coiled tungsten filament frosted light bulbs were manufactured from 1925 to about 1935 or onward.  If the bulb should have the MAZDA trademark and the GE monogram on label or sticker [see A44a?] affixed to outside surface of bulb or to stem tube inside bulb, bulb was manufactured from 1925 to 1926, when labels were discontinued and etched trademarks appeared.  If the bulb should have MAZDA, GE monogram and the wattage and/or voltage etched on the top of the bulb [see A44], bulb was manufactured from 1926 to 1945.  If the bulb has the GE monogram and the wattage and/or voltage etched on top of bulb but WITHOUT the MAZDA trademark, which was discontinued in 1945, bulb was manufactured from 1945 onward.  Double-coiled tungsten filament inside frosted light bulb manufactured from 1935 onward to this day.  If the bulb should have MAZDA, GE monogram and the wattage and/or voltage etched on top of bulb [see A44], bulb was manufactured from 1935 to 1945.  If the bulb has the GE monogram and the wattage and/or voltage etched on top of bulb but WITHOUT the MAZDA trademark, which was discontinued in 1945, bulb was manufactured from 1945 onward.  Three-watt inside-frosted lamps (not a lamp with a rating of 3 watts), also known as three-way lamps, were first introduced in December of 1933.  If the bulb should have MAZDA, GE monogram, the three wattage ratings and/or the voltage etched on top of bulb (see similar etching: see A44) bulb was manufactured from 1933 to 1945.  If the bulb has the GE monogram, wattage and/or voltage etched on top of bulb but WITHOUT the MAZDA trademark [see Figure 209t?], which was discontinued in 1945, bulb was manufactured from 1945 onward.

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