As a sophisticated steel pipe producer in China, we often conduct the second testing in advance. Before production, choosing and checking the suitable raw material is fundamental to the overall construction project. In terms of checking, do you know the testing aspects it contained? At first, we may check the surface of our products to avoid obvious scratching or rusting. It is well known to us that steel pipe surfaces should be evenly without grease or oil. Smooth surface is benefit to make a tight-fitting components. Secondly, gauging thickness is also involved in the testing process. Thickness must be precise in order to accord with the requirement of you. Besides, zinc layer is also very important for customers. Last but not the least, we can have third party checked our steel pipes according to the request of customers. as we have a process of welding when manufacturing, the surfaces of steel pipe may be not flat which can not meet the construction industry standards. In order to produce practical products, flattening weld joint applied to round steel pipes and square steel pipes is crucial to the overall manufacturing process. Our small steel pipes can be inserted in large scale pipes, besides, our steel pipes are equipped with other accessories as it seeks to prevent wires from scratching when threading. In addition to flattening inside or outside weld joints, we can also ensure the surface is glossy with solid structure. Contact us: enquiry@fwssteel.com Tel/Whatsapp: +8613388081802