Looking for a blackening solution

We are manufacturers of high tensile fasteners.We use High Alloy Steels for making these products.All these products are heat treated to achieve the desired mechanical properties.After heat treatment, the blackening compound is used for rust preventive coating as a mixture of water and compound and after the tempering operation the fasteners are dropped into the blackening compound through a conveyor. The ratio of the compound is maintained by measuring the pH level.

We understand that some of our Indian manufacturers of these items are using BLACKER-4929 OF NIPPON GREASE CO. LTD.,JAPAN. We in fact are looking for a blackening compound equivalent to BLACKER-4929 OF NIPPON GREASE.

Presently we are not using any blackening compound instead, achieve BLACK COLOUR by lowering the temperature in the tempering furnace to 160 °C to 170 °C but we are not able to get the optimum colour and surface coating is also not as good as in Taiwanese products.

Hence in order to achieve surface finish and rust preventive coating same as of Taiwanese products.We are looking for a blackening compound equivalent to BLACKER-4929 or superior then it if possible as to what blackening compound they are using . Please help us in this matter and arrange to sent Technical Literature.

Looking forward for your early reply.

With best regards,

adv.