... @ xindayu.com Some questions that you might be concerned:1. Are you Trading or Manufacturing company ? Yes ... the quantity of an order is usually not less than 20 tons. 3. Do you guarantee material AISI ... ,240,320, polish 400,600, hairline.5. Do you keep all pipes in untreated surface or in grinded ... it untreated, or grinded or polished.6. Do you have your own polishing equipment? Yes, we have ...