1、Use range：
Used for all our ferrite product appearance check, as the proof of product leaving the factory

2、Cited standard：
GB9634-88 magnet oxide opponent appearance flaw limit criterion guide

3、Standards as following：
1. Size tolerance in not beyond the required range, if no special requirement, standard tolerance (±2%) is available.
2. Clean magnet body, without fragment and magnet powder, consilient surface burnished degree.
3. Without layer crake, ring crake, and craze phenomena
4. Verticality, parallel, and concentricity are customized.
5. Stipulations as following:
1; Depth over 0.8mm is not permitted
2; Length classification as following:
A: Product below D10mm, length is not above the 4.5% perimeter.
B: D10mm-D20mm product or perimeter summation between 31.4mm-62.8mm, length is not above the 4% perimeter.
C: D20mm-D30mm product or perimeter summation between 62.8mm-94.2mm, length is not above the 3.5% perimeter.
D: D30mm-D40mm product or perimeter summation between 94.2mm-125.6mm, length is not above the 3.0% perimeter.
E: D40mm-D50mm product or perimeter summation between 125.6mm-157mm, length is not above the 2.5% perimeter.
F: Product over D50mm or perimeter summation over 157mm, length is not above the 2.0% perimeter.
G: area is calculated if not over the max length
6. The length and width is not allowed over 20% relevant thickness
7. The depth is not allowed 0.8mm
8. Sand holes over 1mm, and length over 0.5mm are forbidden
9. Thin crack is allowed, but the length is not over the 50% relevant length, width not over 0.5mm, and depth not over 1mm.
10. With ring length is not allowed over 150% relevant perimeters, and without obvious crake.
11. Incising product depth is not over 0.05mm
12. Incising product is not allowed 88 degree (the right angle side)
13. The difference between upper and nether diameter of the outside milling product is not over 0.02mm.
14. the outside milling product with the obvious plane is forbidden to as the finished product
15. Product with the obvious failed milling is not allowed to be as the finished product, but the product, which failed milling is between the required range, is allowed to be as the finished product.

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