This International Standard specifies the dimensions and designation of countersinks for countersunk head screws with a head configuration in accordance with ISO 7721. This International Standard is applicable to the following types of screws: — slotted countersunk flat head screws according to ISO 2009; — slotted countersunk raised head screws according to ISO 2010; — slotted countersunk flat head tapping screws according to ISO 1482; — slotted countersunk raised head tapping screws according to ISO 1483; — cross-recessed countersunk flat head screws according to ISO 7046-1 and ISO 7046-2; — cross-recessed countersunk raised head screws according to ISO 7047; — cross-recessed countersunk flat head tapping screws according to ISO 7050; — cross-recessed countersunk raised head tapping screws according to ISO 7051; — cross-recessed countersunk flat head drilling screws according to ISO 15482; — cross-recessed countersunk raised head drilling screws according to ISO 15483; — hexalobular socket countersunk raised head screws according to ISO 14584; — hexalobular socket countersunk flat head tapping screws according to ISO 14586; — hexalobular socket countersunk raised head tapping screws according to ISO 14587.