Connector terminals can be tinned in three ways, namely, pre-tinning, pre-coating and electroplating. Tin is relatively soft, relatively cheap, and easy to solder, with a coating thickness of 2-12μm. Brass or bronze can be tinned at 110 degrees and steel at 190 degrees. Electroplating on connector terminals is a better electroplating method for existing electric contact parts. Soft, insoluble in acid, with good electrical conductivity. The plating thickness is usually 0.4-3.5μm.