Position: This standard consults use international standard ISO 9177-2 " mobile pencil, the 2nd part: Classification of black lead core and dimension " .
1 theme content and suitable scope
Method of requirement of the classification that this standard provided to mobile pencil uses core of black lead pen, technology, experiment, test gauge wait.
This standard is applied to use black lead core with mobile pencil form a complete set. The main and chromatic composition of plumbic core is black lead, the black line mark of generation is had can brush a gender.
2 cite standard
GB 2828 chases programs of batch of examination sampling by attributes to reach sampling table (apply to the examination that approves continuously)
GB 12654 of base paper of coating of GB 827 hectograph writes paper
3 products are classified
3.1 lead core uses main felt data by place, can divide for core of "P" pencil and "C" lead two kinds:" P" lead core states core of;"C" of core of lead of colophony black lead lead represents core of lead of clay black lead.
The nominal diameter norms of 3.2 lead core and chroma earmark must accord with a watch 1 regulation.
Express 1
|
Nominal diameter Mm |
Chroma norms |
|
0.25, 0.35, 0.5, 0.7, 1, 1.4, 2 |
6H, 5H, 4H, 3H, 2H, h, f, HB, b, 2B, 3B |
3.3 lead core presses its quality index, can divide for advanced taste and general class tastes two kinds.
4 technologies ask
Intensity of bending of 4.1 lead core should not be less than the value that expresses 2 regulations.
Chroma of 4.2 lead core is measured with absorbance, its value should not be less than a watch 3 regulations.
4.3 measure plumbic core to slip spent friction coefficient should not be more than the value that expresses 4 regulations.
The wear and tear of 4.4 lead core should not be more than the value that expresses 5 regulations.
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