This standard specifies the appearance and main dimensions of the glass bulb of type B series electric light sources. This standard applies to type B series electric light source glass bulbs.
QB/T 2049.2-1994 history
2013QB/T 2049.2-2013 Glass bulb dimensions for lamps.B series shapes
1995QB/T 2049.2-1994 Glass envelope of electric light source Dimension of B model glass envelope