cast iron inspection plate

详情描述：

Technical requirements of Inspection surface Plate:
The working surface, when inspected visually, shall be free from blowholes, sand holes, cracks, slag inclusions scratches, porous patches and other visual flaws.
The working surface shall be clean and uniform and the other sides shall be painted well.
The plugging of blowholes or porous patches in the working surface with material of a similar composition is permitted provided that such a repair does not affect stability or accuracy.
The raw material of Cast Iron Surface Plate shall be the close-grained cast iron whose hardness is of HB 170~220.
Where tapped holes or inserts are required the necessary work shall be carried out before the working surface is finished.