Malaysia Bunga Raya Series 2002 One Sen Coin With Brass Planchet Error
Rarity: RRRR
Wrong Planchet.
Definition: A wrong planchet error is exactly what the name indicates – a coin struck on a planchet intended for another denomination (domestic or foreign).
The incorrect planchet may have the same composition (e.g. a 20 sen coin struck on a 10 sen planchet) or it may be a different composition (e.g., a 10 sen coin struck on a One sen planchet).

Off Metal Errors
Definition: An off-metal error is a coin struck on a planchet whose composition does not match the composition that normally characterizes the coin.
The most basic type of planchet error is when the wrong planchet is fed into a press. Since both the loading tube and the die collar are sized for the appropriate denomination of coin, only planchets of the correct or smaller size can be struck within the press.

One that is highly sought by collectors, occurs when a planchet intended for a foreign nation's coinage is struck by dies for a Malaysia coin.
It still may occur, however, as planchets are supplied to our mints by commercial vendors, and these vendors also service the mints of other countries. It's not impossible for a shipment of planchets intended for one country to accidentally include those of another.
There are more subtle errors to be considered. An error coin can have the right diameter and the proper metallic composition but the wrong weight and thickness.
Without a doubt, one of the most popular errors collected today is known as the "Wrong Planchet" or "Wrong Metal" errors.

The "wrong planchet" error also frequently occurs when a tote bin fails to be emptied all the way and a planchet remains stuck in a corner or in the groove of a tote bin door. If the bin is then used to transport planchets for a larger diameter blank or planchet, the wayward blanks, still retained in the bin may be transported to a coining operation of another denomination and struck with that denomination's mark.