Customised field in material master

Hi All,

We have added customised fields in material master  and working fine for material creation and change.

1.I created X material (cusomised field value entered) at plant A

2.When i extend the same material from plant A to another plant B,

3.Now the  values in customised field not copying to plant B, instead the customised field shows blank

Provide your suggestion to bring customised values copy to another plant.

Thanks,

Muru