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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/ }9 ~5 s+ \% j
CLASS和GRADE 的意义如下：
- U$ g. _0 O( c$ ~Class 1 Corrosion protective plating
: p; t$ h7 K8 a; v f& CClass 2 Engineering plating5 Q' y# K, J2 ]
" d& V' k6 B; c5 d4 e' Z1 C3 q4 DGrades- Class 1 plating shall be of the following grades
! G+ r/ |5 I5 o/ `# k- P. g8 p: pGrade A 0.0016 inch thick. {! D2 u& W5 N1 \4 a8 j1 x
Grade B 0.0012 inch thick
. E( f2 G% k4 D" qGrade C 0.0010 inch thick2 Y: S, A; U) O
Grade D 0.0008 inch thick8 ?1 g1 a' T; a" ]- T t
Grade E 0.0006 inch thick& z6 ]7 `( X: y, x: V$ R" B- |
Grade F 0.0004 inch thick
; f3 d2 d& y0 y* pGrade G 0.0002 inch thick |
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