DO41

DO-41 is a standardized axial diode package used for rectifier and other power diodes. The designation stands for a diode outline in a 4.0 mm class, and the standard is part of the family of JEDEC/IEC diode outline specifications that define the physical size, lead layout, and polarity marking for through‑hole diodes. The body diameter is approximately 4 to 4.5 mm, with a length that accommodates axial lead components and end caps. The package is typically made of molded plastic or epoxy, and a band or marking on one end indicates the cathode.

In use, DO-41 devices are chosen for relatively higher current handling compared with small-signal, axial packages. They accommodate a broad range of reverse voltages and forward currents depending on the device, and many common rectifier diodes use this form factor. A widely known example is the 1N400x series, which has historically been supplied in the DO-41 package, along with related rectifier devices from various manufacturers.

Compared with smaller axial packages such as DO-35, the DO-41 is larger and capable of higher current ratings, while still intended for through-hole assembly. It is one of several DO-series outlines used in the electronics industry, alongside variants like DO-204 family packages that differ in size and current capacity.

See also: diode packaging, DO-35, DO-204, rectifier diode, JEDEC.