These test methods cover the testing of fibrous-insulated electrical conductors, commonly referred to as magnet wire, which are used in electrical apparatus. The test methods are intended primarily for evaluation of the electrical insulating materials used. It is intended that these test methods be used, except where modified by individual specifications for particular applications. This elongation testing method covers the determination of the elongation of fibrous insulated magnet wire that results in a fracture of the conductor. The electrical resistance testing method covers the determination of the electrical resistance of fibrous insulated magnet wire conductors. The fibrous coverage testing method covers the determination of the quality of fibrous servings on round magnet wire or bare conductor. The measurement of dimensions test methods determine the dimensions of the bare or film insulated conductor and the fibrous-insulated magnet wire. The adhesion and flexibility test method covers the evaluation of the flexibility and adherence of varnished fibrous glass, and varnished or unvarnished fibrous polyester-glass insulating material on either bare conductor, or film-insulated magnet wire. The dielectric breakdown voltage test method covers the determination of the dielectric breakdown voltage in air of insulation on round, rectangular, and square wires at commercial power frequencies.

1.1 These test methods cover the testing of fibrous-insulated electrical conductors, commonly referred to as magnet wire, which are used in electrical apparatus. The test methods are intended primarily for evaluation of the electrical insulating materials used. It is intended that these test methods be used, except where modified by individual specifications for particular applications.

1.1.1 These test methods apply to those magnet wires that are fiber-covered and in which the substrate is bare conductor or is coated with an underlying insulating film as covered by Test Methods D1676. Fiber-covered wires are produced by serving helically or wrapping fibers or fibrous-tape insulation uniformly around the wire in single and multiple layers. The served or wrapped materials are bonded or not bonded to the underlying wire.

1.2 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.