[Samba] group write permission

[Marc Fromm]

Is there a setting in the smb.conf file so that if a user creates a directory or a file, the group permissions retain write permissions to the new directory or file?
Currently when logged on to  the linux server itself, if a user creates a directory the group permissions are set to  RWX, but with a samba connection the permissions are set to R-X only.

Thanks

Marc