How to polish 304 stainless steel square tubes?

304 stainless steel square tube is favored by people for its advantages of corrosion resistance, oxidation resistance, high strength, easy processing, convenient installation, and long service life. Many people prefer slightly brighter surfaces when purchasing stainless steel square tubes, and polishing can change the surface brightness of stainless steel tubes. This article discusses how to polish 304 stainless steel square tubes.

What is polishing?

First of all, let’s understand what polishing is. Polishing refers to a process of reducing the surface roughness of a workpiece using mechanical, chemical, or electrochemical effects to obtain a bright, smooth surface. It is a process of modifying the surface of a workpiece using polishing tools and abrasive particles or other polishing media. Polishing does not improve the dimensional accuracy or geometric accuracy of the workpiece, but aims to achieve a smooth surface or mirror gloss.

How to polish 304 stainless steel square tubes?

There are also many methods to polish 304 stainless steel square tubes. Currently, mechanical polishing and electrolytic polishing are relatively used more. Different polishing methods have different differences, and there are also differences in cost.

Mechanical polishing mainly involves grinding and polishing the internal surface layer. The polishing rod is placed inside a 304 stainless steel square tube, which drives the inner paddle wheel to rotate at high speed. During continuous rotation, the uneven surface layer inside the stainless steel tube can be polished and ground. Generally, mechanical polishing also includes rough polishing and fine polishing. For some products with relatively high requirements, fine polishing is necessary. During fine polishing, the 304 stainless steel square tube needs to be coated with an appropriate amount of polishing wax to enhance the brightness of the surface layer. This polishing method also has a relatively high cost.

Mechanical polishing can make 304 stainless steel tubes have good flatness and brightness, but it requires high labor intensity, serious pollution, cannot process complex parts, and has high investment and cost. The gloss lasts for a short time, and it is prone to feeling stuffy and rusting.

Electrolytic polishing is more labor-saving than mechanical polishing. However, it requires electrolytic tools and equipment. The 304 stainless steel tube is used as the anode, and the insoluble metal side is used as the cathode. Then, both electrodes are placed in the electrolytic tank and powered on for electrolytic polishing until the desired surface brightness effect is achieved.

This polishing method is relatively more expensive, but the actual polishing effect is better than mechanical polishing. After polishing, the oxide layer on the surface of the stainless steel tube will be destroyed, so it is necessary to passivate the surface with an acidic solution to maintain its anti-corrosion properties. Otherwise, it will cause the surface of the stainless steel tube to easily rust, which will be counterproductive.

The above are two common methods to polish 304 stainless steel square tubes. The polished stainless steel tube should meet quality standards, with a surface brightness of over 520#; the polished tube surface should be smooth, without wax marks, dents, scratches, pressure points, or spiral marks; the tube mouth should be smooth, without bumps, chipping, wax residue; the square tube body should have a curvature of less than 0.5 cm.

Conclusion 

Thank you for reading our article and we hope it can help you to know how to polish 304 stainless steel square tubes better. If you want to learn more about stainless steel square tubes, we would advise you to visit Sino Stainless Steel for more information. 

As a leading supplier of stainless steel products worldwide, Sino Stainless Steel offers customers high-quality stainless steel strips, stainless steel coils, stainless steel plates, stainless steel sheets, stainless steel bars, and stainless steel tubes at an extremely competitive price.