Transistor Package Dimensions

TO-258 Package

Transistor Packages TO-258 Case style, with Metal Tab

TO-258 Transistor Package out-line and Dimensions
TO-258 Case, 3-Terminal Package

The TO-258 transistor is a through-hole device, with three leads and a tab. Although not shown the leads may also be bend upwards, but a bit less common. Another variant uses semi-flexible leads with the origins being rigid which is even less common.

Tab mount. A type of package which provides a method of readily attaching one surface of the semiconductor device to a heat sink to achieve thermal management of the case temperature. If required a metal washer and thermal grease could also be used on the tab.

Similar packages, 3-Terminal TO-257, and TO-254 [with different dimensions].

Semiconductor devices that use the TO-258 package include;
2N7367; Insulated Gate Bipolar N-Channel Transistor

Editor note; this package does not appear to be that common, or currently in common usage.
However the diagram and the dimensions are valid, as shown.

The listing to the left provides three other pin examples of devices that could use this package. However because there are some many examples, no specific device numbers are provided.

This link provides all the other Semiconductor Packages provided on this site.

Transistor Package
Flange-Mounted 5.08 Spacing

TO-258 BJT Terminals:
Lead 1, Collector.
Lead 2, Emitter.
Lead 3, Gate

TO-258 Voltage Regulator:
Lead 1, Adjust.
Lead 2, V out.
Lead 3, V in

TO-258 Dual Schottky Rectifier:
Common Cathode
Lead 1, Anode.
Lead 2, Cathode.
Lead 3, Anode

Common Anode
Lead 1, Cathode.
Lead 2, Anode.
Lead 3, Cathode

Lead 1, Cathode 1.
Lead 2, Anode 1, Cathode 2.
Lead 3, Anode 2

FETs / BJT Manufacturers
Heat Sink Manufacturers

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Modified 6/13/15
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