A-Type Light Bulbs

A-Type light bulbs are the most recognizable and widely used bulb shape in North America, representing the classic "light bulb" silhouette that's been illuminating homes and businesses for over a century. The distinctive pear-like shape with its rounded top and narrower base has become synonymous with lighting itself, appearing in everything from table lamps and ceiling fixtures to appliances and decorative applications. The "A" designation stands for "Arbitrary," reflecting the original arbitrary nature of this design when Thomas Edison first commercialized the incandescent bulb. Today, A-Type bulbs remain the most common choice for general lighting needs, valued for their familiar appearance, reliable performance, and universal compatibility with standard medium base (E26) sockets found throughout North American homes and businesses.

The A-Type family encompasses several size variations, each identified by a number that represents the bulb's maximum diameter in eighths of an inch. The most common is the A19, measuring 19/8 inches (approximately 2.375 inches) in diameter, which has become the standard household bulb size. Smaller A15 bulbs, at 15/8 inches in diameter, work perfectly in applications where space is limited, such as ceiling fan light kits, small table lamps, and appliance lighting. Larger A21 and A23 bulbs provide increased light output and are often chosen for fixtures requiring more illumination or where the larger size is aesthetically desirable. Despite these size differences, all A-Type bulbs share the same fundamental design principles: an efficient shape that distributes light effectively in all directions, making them ideal for general ambient lighting where you want light to spread throughout a space rather than focus in a specific direction.

While LED versions of A-Type bulbs have gained significant market share due to their energy efficiency and longevity, traditional incandescent and halogen A-Type bulbs continue to serve important roles in many applications. Incandescent A-bulbs produce warm, inviting light with excellent color rendering that many people prefer for residential settings, especially in dining rooms, bedrooms, and living areas where ambiance matters. The continuous spectrum of light from incandescent technology renders colors naturally without the subtle color shifts that can occur with some LED alternatives. Halogen A-bulbs offer a middle ground, providing better energy efficiency than standard incandescent while maintaining the warm glow and superior color quality that many users value. Both technologies offer instant full brightness without the brief warm-up period that some other bulb types require, and they're fully dimmable with standard dimmer switches without compatibility concerns or specialized controls.

The versatility of A-Type bulbs extends to their wide range of available wattages, voltages, and special features. You'll find options ranging from low-wattage bulbs for nightlights and ambient lighting to high-wattage versions for spaces requiring substantial illumination. Standard 120-volt options work in typical North American household circuits, while 130-volt bulbs offer extended life by operating slightly under-rated voltage on standard 120V circuits, making them popular choices for hard-to-reach fixtures or commercial applications where maintenance costs matter. Specialty versions include rough service bulbs with reinforced filaments for vibration-prone environments like garage door openers and industrial settings, three-way bulbs offering multiple brightness levels from a single bulb, and long-life variants engineered to reduce replacement frequency in applications where changing bulbs is inconvenient or costly.

For homeowners, contractors, and facility managers, choosing the right A-Type bulb involves considering several factors beyond just wattage. Light output measured in lumens tells you how bright the bulb will be, while wattage indicates energy consumption. Color temperature affects the perceived warmth or coolness of the light, with standard incandescent bulbs typically producing a warm 2700K glow that most people find comfortable for living spaces. Base type is virtually always medium (E26) for A-Type bulbs in North America, ensuring universal compatibility with standard sockets. For specific applications like ceiling fans, dimming circuits, enclosed fixtures, or outdoor locations, selecting bulbs rated for those conditions ensures proper performance and longevity. Many fixtures specify maximum wattage ratings that must be observed to prevent overheating and fire hazards.

At Norman Lamps, our extensive A-Type bulb inventory includes every common size and configuration, from compact A15 fan bulbs to larger A23 options, in various wattages and special-purpose versions. Whether you're maintaining existing installations, retrofitting fixtures, or simply restocking your supply of the most fundamental light bulb design, we have the selection and expertise to help you find exactly what you need. Our product specifications include all the technical details necessary for confident selection, and our team understands the nuances of different A-bulb applications well enough to guide you toward the best choice for your specific situation. Browse our A-Type subcategories below to find the perfect bulb for your application, or contact us if you need assistance identifying the right replacement or alternative for your needs.