Standard
Historical
Last Updated: Dec 12, 2025
Track Document
ASTM D3955-20
Standard Specification for Electrical Insulating Varnishes
Standard Specification for Electrical Insulating Varnishes
D3955-20
ASTM|D3955-20|en-US
Standard Specification for Electrical Insulating Varnishes
Standard
D3955 Standard Specification for Electrical Insulating Varnishes>
new
BOS Vol. 10.02 Committee D09
$
77.00
In stock
ASTM International
Abstract
This specification covers the tests and values for electrical insulating varnishes, as supplied, which are suitable for the impregnation and treatment of electrical coils and windings applied by dip process. The varnishes are classified according to grades: Grade DA; Grade DO; Grade DM; Grade DS; Grade DW; and Grade DT. This specification covers both flexible and rigid, solvent and solventless insulating varnishes. The insulating varnishes are classified according to thermal classes: Class 130; Class 155; Class 180; Class 200; and Class 220. Quality conformance tests shall be performed to conform to the specified requirements.
Scope
1.1 This specification covers the tests and values for electrical insulating varnishes, as supplied, which are suitable for the impregnation and treatment of electrical coils and windings applied by dip process.
1.2 Varnishes, flexible or rigid, included in this specification are:
Grade DA—Air-dry
Grade DO—Organic solvent containing, baking,
Grade DM—Reactive diluent containing,
Grade DS—Silicone,
Grade DW—Water containing, and
Grade DT—Thixotropic.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
Note 1: This specification resembles IEC 60455 in title only. The content is significantly different.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.