Custom Anodizing
Laser Engraving & Silk Printing
Powder Coating & Spray Painting
Blackening & QPQ Processing
Electrophoresis & Electroplating
Other Surface Treatments
We once received some customers inquried about stainless steel products blackening. Our surface treatment engineer's answer is, steel can do blackening, stainless steel can only use QPQ process to achieve the surface black effect. PROMETAL CNC Co. has processed both steel and stainless steel prototype and low volume production of products, so it is also experienced in the surface treatment of steel and stainless steel. If you have a project in this area, please send us a 3D/CAD file for a free quote. We will reply you within 2 hours. If you have a custom part to develop, please send us an email to to GET A FREE QUOTE.

Blackening characteristics
Blackening principle is to immerse the product in a strong oxidizing chemical liquid to produce an oxide film on the metal surface to isolate the air and achieve rust prevention. The process is applicable to steel materials, such as: alloy steel, carbon steel, high speed steel, stainless steel, etc.; it is widely used in instrument housings, low volume production parts, automotive parts, motorcycle parts, non-standard parts, mechanical precision parts, etc.

QPQ processing characteristics

QPQ processing, which is an abbreviation of Quench-Polish-Quench, refers to the ferrous metal parts placed in two different salt baths, which penetrate into the metal surface to form a composite layer through various elements, thereby modifying the surface of the parts. It has good wear resistance, fatigue resistance, corrosion resistance and small deformation. The process is applicable to steel materials, from pure iron, low carbon steel, structural steel, tool steel to various high alloy steel, stainless steel, cast iron Etc.; commonly used in various industries of prototype, precision parts, non-standard and large parts, especially in automotive parts, motorcycle parts, mechanical parts, machine parts, electrical switches, tools and tools are widely used. Please contact us for a free quote. Our email is