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发表于 2008-11-29 19:11:27
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来自： 中国北京
QQ-N-290是美国的电镀镍标准4 q# K. }5 f2 @& W
CLASS和GRADE 的意义如下：
4 \) b) I6 m5 J: w8 @2 UClass 1 Corrosion protective plating
& p7 a* T- l: c, v t9 d( b/ |Class 2 Engineering plating- o* e. D& j" W# k0 m. N
8 Q5 B4 Q. i2 Y0 H" U# b l9 _% }& SGrades- Class 1 plating shall be of the following grades1 E4 |) R7 _# H2 _4 t
Grade A 0.0016 inch thick5 C5 I! V( E3 C! O$ G% j6 P
Grade B 0.0012 inch thick$ ]- `; R$ X7 [2 c/ u% ^$ X2 Q
Grade C 0.0010 inch thick
, K' ?) j9 `( L$ d. z' PGrade D 0.0008 inch thick6 Q* b: z# X8 K1 w* O
Grade E 0.0006 inch thick- y, o6 f) b/ k9 L. s
Grade F 0.0004 inch thick2 [" v6 j- p( J7 T; D" ?
Grade G 0.0002 inch thick |
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