IEC 60317-4:2015 specifies the requirements of solderable enamelled round copper winding wire of class 130 with a sole coating based on polyurethane resin, which may be modified provided it retains the chemical identity of the original resin and meets all specified wire requirements. The range of nominal conductor diameters covered by this standard is: - Grade 1: 0,018 mm up to and including 2,000 mm; - Grade 2: 0,020 mm up to and including 2,000 mm. The nominal conductor diameters are specified in Clause 4 of IEC 60317-0-1:2013. This fourth edition cancels and replaces the third edition published in 1990, Amendment 1:1997 and Amendment 2:1999. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - new 3.2.2 containing general notes on winding wire, formerly a part of the scope; - new 3.2.3 containing requirements for appearance; - revision to references to IEC 60317-0-1:2013 to clarify that their application is normative; - consolidation of 17.1 and 17.2 of the solderability requirements; - revision to Clause 19, dielectric dissipation factor; - new Clause 23, pin hole test. Keywords: insulated wires used for windings This publication is to be read in conjunction with IEC 60317-0-1:2013.