Pretty sure this is a magnetic version of China Cash N#45601

Very close to N#45601 but not the same mintmark. Looks like a brass version but is magnetic when a more powerful magnet is near it. So this coin is more likely a brass coin with iron impurities?

Weighs ~3.4g,

Measures 23mm

Topic bump.

Hello

More this one

N#30355

I think it's 22.539 

And to save money, (or sometimes embezzle money,   mens are ugly ( a french joke from the film "deux heures moins le quart avant Jésus Christ)) 

the alloys weren't of very good quality.

Quite a few cash style coins contain small quantities of ferrous material that can make them slightly attracted to strong magnets. Some also contain quantities of lead and other not so nice things so don't give them to small Children that might put them in their mouth or people that don't know how to wash their hands.