The National Electrical Manufacturers Association (NEMA) published ANSI/ANSLG C81.61, “Electrical Lamp Bases—Specifications for Bases (Caps) for Electric Lamps” and ANSI/ANSLG C81.62, “Electric Lampholders”. Both documents were last revised in 2007.

C81.61 and C81.62, respectively, cover lamp bases (caps) and
lampholders for electric lamps. Both standards were revised to include
G24 lampholder and base dimensions.

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