ERROR ? Sin kiang 1929 china 10 cash coin

Is this an error…..looks like lamination error

I see a heavily circulated, very worn coin with post mint damage, verdigris, and no lamination error.

https://minterrordatabase.com/edu/lamination_errors.html

I think this shows the reason for the OP's question, which I think is based on the occurrences at 1600 and 2230?

The edges n coin have a layer of metal not connected…...what kind of defect is this????

judging from the amount of wear on this coin I would guess that the delamination is part of the damage, would be a proper error if it was minted like this but I can't see that being likely

I don't think it's wear…..I've seen auctions in AU and UNC or XF and it has the same details but it has mint red ..the reason it doesn't have sharp details is the fact it has an very weak strike as this was a warlord coin with bad technology not circulation wear….

Other examples I see of these types of coin just call it “environmental damage”. 

It's very difficult to tell if it was minted like this as there is other damage and wear to the coin. 

It should be..I'm Chinese my self and I went to Chinese coin shops and asked about this they said it was indeed the fact that many uncs or any grade are in bad condition and strikes as the strikes were weaks and errors were common to happen because of the shitty technology, thanks tho 

Koking

It should be..I'm Chinese my self and I went to Chinese coin shops and asked about this they said it was indeed the fact that many uncs or any grade are in bad condition and strikes as the strikes were weaks and errors were common to happen because of the shitty technology, thanks tho 

Then why are you asking here? You seem to have already made up your mind. You asked for opinions and you got them. Sorry if we don't agree with what your opinion is. Frankly, this coin is trash. PMD  or Lamination error or not. As said previously, at this point it is impossible to prove either way exactly what happened to this coin in such poor condition 100+ years after it was produced.