The wall thickness of well water filter pipes is typically undersized. The standard undersize for stock well water filter pipes is usually 0.2mm.

Is the so-called "lower tolerance" thickness after the wall thickness commonly referred to actually the actual wall thickness of the filter pipe? Not at all! The filter pipe wall thickness is 6mm, and the filter pipe manufacturer orders 5.8mm steel coils from the steel mill for production. This means that the "lower tolerance of 0.2mm" mentioned by the filter pipe manufacturer simply informs you that we use steel coils with a lower tolerance of 0.2mm, not that the actual wall thickness of the filter pipe is 0.2mm lower. In fact, the thinnest wall thickness of the produced filter pipe is not 5mm, because a 5mm thick steel coil is not uniformly thick; its thickness varies at different places, such as 5.7mm, 5.8mm, 5.9mm, etc. Generally, the thinnest parts of the steel coil are at the edges, so the thinnest parts of the produced filter pipe are also at the weld seams. Therefore, we require filter pipes produced from 5.8mm steel coils, where the thinnest part may be as thin as 5.7mm. If the customer demands a wall thickness of no less than 5.8mm, they should inform the filter pipe manufacturer, who will then order 5.9mm steel coils to produce the filter pipe for them.

It is evident from the previous introduction that the actual wall thickness of the filter pipe is not the nominal wall thickness of the strip steel. If customers desire a filter pipe with sufficient thickness, they need to order strip steel with a wall thickness exceeding the nominal thickness for the production of the filter pipe.