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1 minute to teach you to use the naked eye to identify the real and fake hot-dip galvanized seamless steel pipe

Hi, I’m Max Shi, the CEO of tytsteel.com. With more than 10 years of experience in OEM/ODM steel pipe, I’d love to share with you the valuable knowledge related to steel products from a Chinese supplier’s perspective. Hope you like this article, and please share it or subscribe to our newsletter.

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Now there is a so-called hot-dip galvanized fluid pipe on the market, also called de-galvanized seamless pipe, in fact, it is a high-frequency welded pipe after treatment, the original weld with special equipment or planing off or grinding off and then galvanized. Now the identification of this kind of pipe will be taken out to share with you:

(1) Any planing off or grinding off will leave traces, some are also very obvious;

2) hot dip galvanized de-seamless tube are 6 meters, 9 meters or 12 meters fixed size, genuine hot dip galvanized seamless steel pipe fixed size is very little, because fixed size factory to add a lot of price;

(3) The manufacturers of such tubes for fear of liability, their quality certificates are fluid tubes and do not dare to say that the seamless steel pipe;

(4) see whether its wall thickness is uniform, because seamless steel pipe is made of round steel hot-rolled and perforated, so the general seamless steel pipe wall thickness will have deviation (with the continuous improvement of technology seamless steel pipe wall thickness deviation is getting smaller and smaller, but there are still), and welded pipe, although the welded bar treatment or hot expanding and other procedures, but because his raw material is the strip steel, so his wall thickness is very uniform.

How to identify the appearance of hot and cold galvanized steel pipe

Have you often been troubled to distinguish whether some pipe fittings are cold galvanized or hot-dip galvanized? Of course, many people will say that it is not clear to send to the quality inspection authority, but I personally think that the traditional way of inspection is not only a waste of time and money, but also a waste of time and money.

The following is to introduce a way to identify the two types of fittings

1, the difference is as follows:

Appearance: hot-dip galvanized looks bumpy appearance slightly dark; cold galvanized looks smooth appearance bright;

Thickness: hot-dip galvanized thick, cold galvanized thin;

 cold galvanized

cold galvanized

 hot-dip galvanized

hot-dip galvanized

Bore: hot-dip galvanized bore are plated: cold galvanized bore only two ends;

Corrosion resistance: hot-dip galvanizing is high: cold galvanizing is low;

Marking: hot-dip galvanized at both ends of the hoop with blue ink printing, through the body of the implementation of standards and specifications and models: cold galvanized no.

dn50 hot dipped galvanized steel water pipe

hot-dip galvanized at both ends of the hoop with blue ink printing

2, cold galvanized price is correspondingly low

This is an empirical thing, but observe whether the galvanized layer is flat and even is an important project, there is also a look at the quality of the

Inspection report, field instructions of the supporting documents, if you feel that the documents can not be described, then I recommend using a hammer or something like that to knock the

If you feel that the documents can not explain, then I suggest using a hammer or something to hit the pipe to see if the galvanized layer will come off, if it does, then in all likelihood it is cold plated.

If you have any questions about this article, please feel free to contact us, our company as the production of pre-galvanized pipe and hot galvanized pipe manufacturers are happy to answer your questions!

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