Requirements 4.1 Appearance requirements The appearance of sintered NdFeB magnets for hub motors should be clean and free of deformation. The surface of the product should not have defects such as cracks, blisters, inclusions, and corner peeling that may affect use. 4.2 Dimensional requirements The dimensions of sintered NdFeB magnets for hub motors should comply with the technical requirements of the drawings. Unless otherwise specified, the main dimensions and general dimensions of the magnets should comply with the provisions of GB/T13560. 4.3 Main magnetic property requirements 4.4 Temperature resistance requirements 5 Test methods 5.1 Appearance The appearance quality of the product shall be visually inspected. 5.2 Dimensions The size and shape deviation of the product shall be detected using micrometers, calipers, feeler gauges, standard rims and other measuring tools that meet the accuracy requirements and comply with national measurement standards, or special measuring tools negotiated and confirmed by both parties. 5.3 Main magnetic properties 5.4 Temperature resistance requirements 5.5 Coating