KeystonewasestablishedinHongKongin1969,underitspreviousnameKeystoneIndustrialCo.Ltd.,Keystone'smainproductlinesincludecopperwire,LowVoltagePowerCable,ControlCableandTelecommunicationCable.Keystone'sconstanteffortstoupgradeitsqualitystandardandexpanditsproductlinesledtotheformationofajointventurewithPhelpsDodgeCorporation(PDC)ofUnitedStatesofAmericain1991.PDCisthesecondlargestcopperproducerintheworld,aftertheChileanGovernment.PDCsubsidiariescompanies,PhelpsDodgeInternationalCorporation,hasover17c…（未完，全文请 查看更多 ）