Finland 5 markkaa KM31a - same KM two compositions

My opinion is that Finland 5 markkaa KM31a (1946-1952) should be devided into two types. Years 1946-1949 has a composition of apprx 650 Cu 350 Zn (brass), but 1950-1952 has a composition of 900 Cu, 70 Zn, 30 Al. That later composition we call as Aluminium brass. You can find that information from Finnish catalogs. In addition to that we should add few more variations but I will arrange the details later.

No, my opinion (and the definition of brass) is that brass can have different amounts of copper up to 95% with zinc added, plus other elements. So the 1946-1949 coins are Brass, as are the 1950-1952 coins.

All coins are Brass, no design, weight or size changes. The Km number is 31a for all years - why should Numista separate them further and then not conform with the SCWC or Km ident, sort of confusing just for the sake of it. 

Please put that information in the comment section.

I thought that if the composition of a coin is different  coin types are split on independent pages (as mentioned on Numista Guidelines). Also I would like to mention that the coin catalog made by The Finnish Association of Numismatic Societies has split these coins on independent pages (types). I believe we can call both compositions as brass but the fact is that these coins have a different composition.

Ollisaarinen

I thought that if the composition of a coin is different  coin types are split on independent pages (as mentioned on Numista Guidelines). Also I would like to mention that the coin catalog made by The Finnish Association of Numismatic Societies has split these coins on independent pages (types). I believe we can call both compositions as brass but the fact is that these coins have a different composition.

 

Totally agree when changing from Brass to Copper or visa versa, also when silver or gold is reduced in fineness, and now when new coins are minted - but in this case it is just pointless. A note in the comments is worthy enough.