1. Put the screw into the hydrochloric acid bucket, pickling and activating the screw surface;
2. Put the screws into the cleaning bucket, Barros clean;
3. Put the cleaned screws into the blackening tank for blackening treatment (the surface becomes black, not fading is appropriate). The blackening tank is configured as: 5% blackening liquid plus 3% hydrochloric acid 5% plus 90% normal temperature water;
4. Put the screws into the cleaning bucket and clean the screws;
5. Place the cleaned screws into the table adjustment slot for table adjustment. Table adjustment configuration: table adjustment 2% with room temperature water (PH> 8);
6. Put the adjusted screws into the phosphating tank for phosphating. Phosphating configuration: phosphating solution 9% and water 90%, heating 90 degrees for 5-10min, the screw surface can be evenly phosphating;
7. Put the screws into the cleaning bucket and clean the screws;
8. Put the cleaned screws into the spin drying bucket, spin the screws dry and dehydrate;
The last step is to put the dried screws into the bucket equipped with anti-rust oil, soak, soak evenly.