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English
The general requirements for surface defects of nuts are shown in Table 1.1-36.
Table 1.1-36 General Requirements for Nut Surface Defects
(1) Types and general requirements of surface defects
(2) Acceptance inspection method
1) Non destructive inspection: It can be magnified 10 times for visual inspection or other non-destructive inspections, such as using magnetic technology or eddy current;
2) Destructive inspection: After removing surface coatings and plating, if surface defects that may exceed the allowable limit are found, the sample with the most severe surface defects should be selected for destructive testing (GB/T 3098.12 and GB/T 3098.14);
3) Arbitration test: The arbitration inspection of nuts made of easy cut steel should be carried out according to GB/T 3098,14 by performing a hole expansion test on the nuts. According to the agreement between the supply and demand parties, additional tests can be conducted in accordance with GB/T 3098.12;
Note: Applicable scope of the standard: nominal diameter of the thread is 5-39 mm; product grades A and B; All performance levels in accordance with GB/T3098.2 and GB/T3098.4, except as otherwise specified in the product standards or with special requirements from both the supplier and demander.
