What does this number measure?
A discrete NPN bipolar transistor used to amplify or switch small signals. The onsemi 2N3903/D datasheet, revision 9 of August 2021, gives 4.32 to 5.33 mm for package dimension B. This reference adopts the maximum limit of 5.33 mm; it is neither an average nor a measurement of a specific specimen. Lead length is not the dimension compared, and the leads are drawn in simplified form. The silicon transistor is inside the package. Process names such as “2 nm” or “3 nm” do not specify a universal dimension for an entire transistor.
Compare the stated dimensions
The comparison uses the number in each fact sheet: altitude, height, diameter, length or distance, depending on the reference. Two values in metres do not necessarily describe the same property.
Compare with 2N2222A · TO-18 metal-can transistor in the explorer →
Source and limitations
Manufacturer's datasheet consulted on 30 October 2026. The drawing shows a documented maximum envelope, not the measured size of an individual unit. Package dimensions and versions vary between manufacturers; this entry describes only the stated reference and source.
An original drawing of an electronic package, not a photograph. The common scale factor measures its documented maximum external width; pins and perspective are simplified and do not represent a measurement of the internal silicon die.