Surface Finishes

Introduction to Protective TreatmentsThere is currently an almost endless choice of surface treatments available to protect components against numerous working conditions.We have chosen to list below some of the most commonly requested finishes, if however the finish you are considering is not listed, please call us to discuss your requirements.The only rule to bear in mind is:- DO NOT USE ELECTROPLATING - This process will cause the disc springs to become brittle and fail!BrowningA process to produce an oxidised surface onto which a corrosion inhibiting oil can be applied.Phosphating (zinc phosphate and oil)This is the standard surface treatment usually applied to carbon steel disc springs, this finish is usually sufficient to prevent corrosion in unexposed applications and during transportation and storage. However in applications where the disc springs will be subjected to the elements a higher level of protection would be required.Mechanical Zinc PlatingA mechanical plating process that allows a substantial thickness of zinc to be applied to the surface of the disc spring without the risk of hydrogen embrittlement associated with normal electroplating.

A passivation would then be applied to seal the plating.Electroless Nickel PlatingA method of chemically depositing a nickel coating to the disc spring thus avoiding the associated problems of hydrogen embrittlement, this process produces a smooth satin finish with a high degree of corrosion resistance which justifies its increased cost.Delta Tone - Delta SealAn inorganic coating made up of aluminium and zinc compounds is applied and then baked onto the disc spring to achieve an electrically conductive and highly corrosion resistant surface finish. There is no risk of hydrogen embrittlement with this prodess.Delta seal is a strongly adhesive organic compound which is applied and then backed onto the disc springs.Both of these highly corrosion resistant coatings are heavy metal free.