E39 and E40 are other sets of bases you can use interchangeably. However, it is not a common practice to do so. That’s because the thread outside diameter differs by only one millimeter (0.04 inches), yet the pitch is slightly different. Therefore, it is more likely for an E40 cap to fit into an E39 holder rather than the other way around. For example, a T10 wedge base is commonly used in automotive taillights, while a T15 wedge base is used in some turn signal and brake light applications.

Pin-based bases are suitable for compact fluorescent lights and fluorescent tubes. Consider the Diameter

When dealing with E12 light bulbs (primarily for decorative lighting), there are two things you should focus on including: Why are the two important? Well, essentially, E12 bulbs are helpful in decorative applications. So, unlike the general lighting bulbs, E12 bulbs have to yield a light of exceptional quality to best fit their designated application.

Color temperature: Color temperature refers to the color of the light emitted by a light bulb. Higher color temperatures typically produce white light, similar to daylight, while lower color temperatures produce warm white light, similar to the light color of traditional incandescent bulbs. Choose a color temperature that suits your needs and decorating style.These bulbs come with a 14-mm diameter screw, just as the name suggests, making the bulb about the same width as your little finger.

Bulbs with E12 bases are commonly used for decorative applications, such as chandeliers, wall sconces, Christmas lights, restaurant pendant lights, ornamental lights, residential or commercial string lights, and night lights. Many bulbs with these bases are designed to mimic the look of a candle flame. As the name suggests, the E17 base has a diameter of 17 millimeters. This is typically larger than the common E12 base and smaller than the E26 base.These are the most popular light bulb bases. Bulbs with these bases are also the most popular in the market.