Used for fastening: insulation between the screw and the metal sheet of the heating element to prevent short circuit of the tube and transistor .
Purpose: For use with heat sink gaskets.
Typical specifications: TO-220, TO-220A, TO-220B, TO-220C, TO-220D, TO-220E, TO-3, etc.
There are more than 300 sets of non-standard specifications. New and old customers are welcome to order.