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black hex head screws must be thoroughly degreased after blackening.

Because the blackening liquid at normal temperature is acidic and has no degreasing function, the grease must be removed during the previous treatment process. There are many options for degreasing methods, which can be selected according to personal conditions. After degreasing, it is best to thoroughly rinse and rinse, and remove the oil floating on the rinse tank in time to prevent the workpiece from being contaminated again. The way to check the degreasing effect is to observe that there should be a uniform and continuous water film on the surface of the workpiece. If water droplets or uneven and discontinuous water films appear, it means that there is still grease on the surface that has not been removed, and rework should be done immediately.

8.8 grade black zinc plated hex bolt factory

8.8 grade black zinc plated hex bolt workshop real shot

8.8 grade black zinc plated hex bolt packing