①Inspection of China Nut; visually inspect the surface quality of the bolts. Any burrs left by machining must be removed and sharp edges must be rounded.
② Manual degreasing; ensure that there is no grease on the surface of the substrate.
③Soak and remove oil; put the bolts in alkaline water and boil to remove the surface oil.
④Pickling: In order to prevent the alkaline degreasing solution from polluting the flash nickel plating tank, electro-activation treatment is carried out with the pickling solution before the flash nickel plating.
⑤ Bolt Factory is electro-activated; use acid solution for electro-activation treatment.
⑥ Nickel flash plating; for low alloy steels, nickel flash plating should be used to increase the bonding strength between the coating and the substrate.