FAQ Frequently Asked Questions

Thin-walled electric-welded pipes are produced on pipe mills by electric-welding of a steel strip, pre-bent in the form of a cylinder. In general, the method for producing thin-walled pipes is identical to the method for producing other electric-welded pipes with regular and thick walls. The differences lie only in the delicacy and accuracy of the equipment adjustment to give and maintain the ideal shape of the circle at all production stages.

The range of electrically welded thin-walled pipes must comply with GOST 10704-91.

There are several views – which pipes are called thin-walled.

Only pipes with a wall thickness of less than 2.5 millimeters.
Pipes, the wall thickness of which does not meet the minimum technical requirements for the test hydraulic pressure established in GOST 10705-80.
In fact, both points of view are correct, because thin-walled pipes are designed and used exclusively for the production of metal products and non-loaded metal structures, where the concept of strength class is far from decisive, and the first place is taken by efficiency and maximum lightening of metal structures or metal products.

Thin-walled pipes are made from hot-rolled or cold-rolled steel strip (strip) from low-carbon grades 08Yu, 08PS and carbon grades 1PS, 2PS, 3PS.

Cold rolled steel destination

Manufacture of metal products for various purposes, from household and school furniture to car mufflers.
Most often used in cases where cold bending, powder painting or electroplating is required.

Hot rolled steel, general

Manufacture of metal products, loaded and non-loaded metal structures, protection of electrical cables. Most often it is used in the production of small construction works with standard methods of protection against corrosion – galvanizing, painting.

Cold rolled steel Hot rolled, general purpose

Assortment

from 10×0.7 to 76×1.5 (rarely 2mm wall)

Assortment

from 19×1.5 to 159×3

Steel grades

08U, 08ps, 1ps, 2ps

Steel grades

1ps, 2ps, 3sp / ps

Hydrotesting

Not held

Hydrotesting

Not held

Maximum deviations in wall thickness
from ± 0.04 to ± 0.15 millimeters Limit deviations in wall thickness
± 0.12 to ± 0.2 millimeters

Steel thin-walled pipes are packed in bundles (packs) weighing from 1 to 5 tons. The bundles are tied with steel tape or wire in three places. A tag is attached to each package indicating the diameter, wall thickness, length, steel grade, batch number or heat. Thin-walled cold rolled steel pipes are often packed in steel boxes for better protection against weathering and mechanical damage.

Thin-walled pipes are stored in open flat areas specially adapted for storage of rolled metal, with a hard surface, or in heated warehouses (preferably).

Thin-walled pipes are transported “in bulk” in open vehicles – gondola cars or cars with an open body. It is not allowed to transport thin-walled pipes together with ordinary pipes or other rolled metal products due to the high probability of damage.

Used in communication pads and in the construction industry, they can withstand colossal loads. The field of application of cold-rolled pipes is determined by GOST 8734-75. The regulated document GOST 8734-75 allows the production of cold-worked pipes from different types of steel – steel 20, steel 10. The cold-rolled seamless steel pipe according to technologies is offered in a diameter from 5 mm to 250 mm with a choice of wall thickness from 0.3 to 24 mm. The most common are cold-worked pipes with a diameter of 10 to 83 mm and a wall thickness of 1 to 6 mm. Tolerances and deviations differ depending on the manufacturing accuracy: in wall thickness – up to 12%, and in diameter – up to 3%. Unlike other pipes (for example, shaped pipes or electric-welded pipes), the price of cold-rolled pipes is much more expensive due to the high energy consumption and expensive equipment.

Many companies on the market offer to buy cold rolled 20 steel pipe. Unchanged positions for many years have been held by the company “OOO NTZ” – a manufacturing plant and a sales center at the same time. The range offers cold-rolled steel pipes, which have different sectional shapes, lengths, diameters and thicknesses. The price per meter for cold-deformed pipes is set, depending on the steel grade taken as a basis, as well as on the complexity of the technological process. It is quite possible to order cold-rolled pipes according to individual requirements, which will have the same unsurpassed quality as other rolled metal pipes, and you can also arrange delivery to Kiev, Dnipro, Krivoy Rog, Kharkov, Lvov, Odessa and other cities of Ukraine.

Cold-worked pipes are made of high-alloy and low-carbon steel. Manufacturing technology is as follows:

1. The steel billet is heated to a high temperature, at which the metal begins to crystallize. This is necessary in order to achieve the required ductility of the metal.
2. After heating, the red-hot workpiece is fed to the rolling machine, where it is stretched and crimped;
3. The prepared pipe is cooled with water and then calibrated;
4. To increase strength, the calibrated pipe is thermally processed;
5. Slicing is made according to the required standards.

The main difference is cooling and heat treatment. Hot-deformed pipes do not undergo such procedures, therefore, their durability and strength properties are lower, although they are cheaper.

As a rule, finished pipes are sorted by length, covered with protective paper or foil, and then packaged in several pieces – the quantity depends on the size of the product. This is a standard type of packaging, but it can be changed according to the customer’s requirements.

According to GOST, a seamless cold-deformed pipe should be a simple rod format with a hollow interior. In addition, the presence of any weld seams or other connecting elements is excluded. Depending on how the pipes are made, the process is divided into several categories:

rolling;
forging;
drawing;
pressing.
One of the most common pipe production methods in factories is rolling. A pipe made using the hot rolling technique is used as a semi-finished product.

A workpiece is made of steel using special equipment equipped with all the necessary elements. Directly the steel itself is selected alloyed or carbon class. The difference between seamless pipes is the possibility of using in adverse conditions and in circumstances with an increased likelihood of mechanical action from the outside.

Pipes made by cold forming have small dimensional qualities that differ significantly from products made by hot rolling and other welded materials. But this fact does not prevent them from winning in other parameters: impeccable dimensional accuracy, ideal quality of seamless structures and the admissibility of the production of thin-walled products.

The main direction of the production activity of NTZ LLC is the production of seamless cold-worked pipes for general use, thin-walled pipes made of carbon and alloy steels for nuclear power, boiler construction, aviation, shipbuilding, machine-building, chemical industries, enterprises of the military-industrial complex (MIC) Ukraine and EU countries.

All pipes that are available at the NTZ plant you can view:

Pipes available

or contact our manager to clarify information