ASTM A1101:16 pdf download

ASTM A1101:16 pdf download.Standard Specification for Sintered and Fully Dense Neodymium lron Boron (NdFeB)Permanent Magnets.
8. Magnetic Property Requirements
8.1 Magnetic properties are listed in Table I.
8.2 The values of magnetic properties listed in the table are specified minimum values at 20 ± 2 °C (68 ± 4 °F), determined after magnetizing to saturation in closed magnetic circuit.
8.3 The specified values of magnetic properties are valid only for magnet test specimens with a uniform cross-section along the axis of magnetization. Properties for anisotropic (magnetically oriented) magnets are measured along the axis of preferred orientation.
8.4 Because of the nature of permanent magnet production, magnetic testing of each lot is recommended, especially for applications where the magnet performance is closely specified. Such magnetic property evaluations shall be conducted in the manner described below. Where the magnet shape is not suitable for magnetic testing, a specimen shall be cut from the magnet using appropriate slicing and grinding techniques, paying attention to any magnetic orientation within the magnet.
8.4. 1 The magnetic properties shall be determined in accordance with Test Method A977/A977M, or by using a suitable, mutually agreed upon magnetometric method.
8.4.2 When magnets are being purchased in the fully magnetized condition, the testing shall determine the magnetic properties from the as-received magnetization state, followed by magnetization to saturation and testing of the magnetic properties from the fully magnetized condition.
8.4.3 When magnets are being purchased in the unmagnetized condition or in an unknown state of magnetization, the test laboratory shall magnetize the test specimen(s) to saturation in the same orientation as the received specimen’s indicated direction of magnetization and measure the magnetic properties from this fully magnetized condition.
8.4.4 When magnets are being purchased in a calibrated, stabilized, or “knocked-down” condition, magnets should be handled with care to prevent exposure to externally applied fields. Refer to Appendix X6 for an explanation of these terms. During testing using Test Method A977/A977M, the measurement should proceed in the second quadrant only, without attempting to saturate the magnet specimen, to avoid changing the magnetization state of the material prior to test.
8.4.5 Other test methods may bc utilized as agreed to between producer and user. Such tests may include the open circuit magnetization Helmholtz test. field strength measurements in a defined magnetic circuit or adjacent to the magnet surface.