You can find metal insignia in black for pin on collar of the Field Jacket or Uniform Coat.
US ArmyRank Insignia Private, E-2 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Private first class, E-3 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Corporal, E-4 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Specialist 4, E-4 burnishedBlack burnished rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Sergeant, E-5 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Staff Sergeant, E-6 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Sergeant First Class, E-7 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Master Sergeant, E-8 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia First Sergeant, E-8 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Sergeant Major, E-9 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA
US ArmyRank Insignia Command Sergeant Major, E-9 burnishedBlack burnished Collar rank insignia for the combat uniformMade in USA