Standard Historical Last Updated: May 01, 2013
ASTM D3251-04(2009)

Standard Test Method for Thermal Endurance Characteristics of Electrical Insulating Varnishes Applied Over Film-Insulated Magnet Wire

Significance and Use

Different combinations of varnishes and film-insulated magnet wire behave differently when exposed to elevated temperatures. This includes different varnishes tested with the same film-insulated magnet wire and a single varnish tested with different film-insulated magnet wire.

This test method is used to determine the effect on the electrical properties of a varnish applied to film-insulated magnet wire when the combination is exposed to prescribed elevated temperatures.


1.1 This test method covers the determination of the thermal endurance characteristics of electrical insulating varnishes and film-insulated magnet wire in combination.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Note 1—This test method is equivalent to IEC 60172.

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Book of Standards Volume: 10.02
Developed by Subcommittee: D09.01
Pages: 2
DOI: 10.1520/D3251-04R09