How to get high quality precision seamless pipe?

What is a precision seamless pipe?

Precision seamless pipe is a pipe material producing by a cold drawn process with high-pressure, high-precision, high-grade finish.

precision seamless tubes 1 - How to get high quality precision seamless pipe?

CDS is popular in the hydraulics, being used to make hollowed chrome plated telescopic cylinders and hydraulic rods. It is also popular for large bore, heavy walled, high pressure hydraulic cylinders. Cold Drawn Seamless tubes also find uses in heavy equipment manufacturing such as cranes and garbage trucks.

precision seamless tubes 2 1 - How to get high quality precision seamless pipe?

Due to the characteristics of high-precision, in precision machinery manufacturing, auto parts, hydraulic cylinders, construction (steel sleeve) industry has a very wide range of applications.

Drawing Process of Precision Seamless Tube

Ultrasonic detector gas leak detection system is different from the specific design of the sensor to sense that it is limited to a specific gas, but rather to detect sound.
Ultrasonic focusing on industrial leak detection, leak detection and predictive maintenance, products and solutions in steel and non-ferrous metals, tobacco and food and beverage, automotive, chemical and oil and gas, mining and cement, glass manufacturing, electricity and cleaning system, military, paper and printing, rail transport, water treatment, infrastructure, subway fan and large air conditioning systems, port automation, and many other industries are widely used.
Any gas leakage through holes will generate eddy currents, ultrasound will be part of the band, making the ultrasonic detector leak detection system capable of sensing any kind of gas leak. Drawing process of precision seamless tube with a detection system scan, you can hear the sound from the headphones leak or see changes in the digital signal. The closer to the leak, the more obvious. If the site noisy environment, can reduce the reception area and shadowing hose antagonistic ultrasound. Also the ability to adjust the frequency of the ultrasonic detector leak detection system also makes the background noise is reduced. You can check the air pressure systems, test pressure used by telecommunications companies and cable. Tanks, pipes, and hoses can be detected by the pressure. And a vacuum system, inter-vortex exhaust, diesel engine fuel intake system, vacuum tanks, marine tanks, watertight doors, material handling systems, pressure vessels and piping inside and outside the gas-liquid leakage.
Drawing process of precision seamless tube detection method can leak air, gas, steam and liquids pipeline and a variety of equipment to be checked. If the ultrasonic generator and attached with the use, but also on the refrigerator, sealed container, air conditioning systems, tires, compressor and various fluids, such as sealed state pipeline inspection, improving the environment, a powerful tool for saving energy.

A considerable proportion of the seamless tubes and pipes manufactured through the cold roll piercing technology undergo subsequent cold forming. The principal reasons behind cold drawing are:

precision seamless tubes 3 - How to get high quality precision seamless pipe?
  • Achievement of closer wall thickness and diameter tolerance
  • Improvement in surface finish
  • To enhance serviceability
  • No premature failure
  • Suitable for critical forming Such as 180˚ Bends
  • Enhancement of mechanical properties of the tube
  • Expansion of product mix towards the lower end of the OD and wall thickness scales.


  • Hollow drawing
  • Stationery drawing or floating plug drawing and
  • Drawing over a mandrel (also known as drawing on-the-bar)

After the goods are cold drawn to sizes, the tubes are put on annealing furnace for heat treatment and normalising.


Post annealing, the goods are passed through a seven roller straightening machine to achieve proper straightening of the tubes.

Eddy current

Post straightening, each tube is passed through eddy current machine to detect for surface cracks and other defects . Only the tubes that pass eddy current are fit for delivery to customers.


Each tube is either oiled with corrosion resistant oil or varnished for surface protection and corrosion resistant as per customers requirement, each tube end is covered by plastic end caps to avoid damage in transit, the marking and specs are put and the goods are ready for dispatch.

The Advantages of Precision Seamless Steel Pipe

1. Precision seamless steel pipe is light weight, high strength, easy for transportation and installation. It is only 1/4 of steel, but the circumferential tensile strength is 180 – 300MPa and the axial tensile strength is 60 – 15OMPa, which is similar to alloy steel. Therefore, the strength is 2 to 3 times of gold steel. So that it can meet different requirements of users, designed to various types of pipeline to withstand internal and external pressure. Precision seamless steel pipe is 12 meters per section, it is easy to install which reduce the cost of lifting and improve the installation speed.
2. Anti-fouling and anti-boring. Precision seamless steel pipe will not be affected by sewage, fungi and other microbial station fester, reduce maintenance costs. Without these pollution, precision seamless steel pipe can be used for a long time. Due to its smooth wall and excellent corrosion resistance, it will not produce scale and microbial, effectively ensure water quality.
3. Good heat resistance, good frost resistance. Below -30 degrees, precision seamless steel pipe still has good toughness and high strength, can be used at the range of 50 ℃ – 80 ℃.
4. Good corrosion resistance. Precision seamless steel pipes can resist acid, alkali, salt, sea water, untreated sewage, corrosive soil or groundwater and erosion of many chemical fluids. Compared to traditional pipes, it generally lasts more than 50 years, which is used in municipal, urban transmission and distribution network. Because precision seamless steel pipe is non-toxic, no rust, tasteless, no secondary pollution to water, no corrosion, they are widely used for drainage industry.
Features and Usage of Precision Seamless

Piercing is the first step of hot-rolled seamless steel pipe deformation, and its role is to solid hollow tube billet dressed as capillary.
Due to wear a capillary surface defects or eccentric (uneven thickness) is difficult to eliminate or reduce the deformation process, therefore, the quality of perforated capillary has a very important impact on the quality of hot-rolled seamless steel pipe. Way pressure tube perforation punching, pushing rotary piercing and piercing. Thick-walled seamless steel mainly used in petroleum geology drilling pipe, petrochemical used in cracking tubes, boiler tubes, pipes and automotive bearings, tractors, aviation and other precision tube structure, its manufacturing process: hot rolled seamless steel tube round → heating → three perforated roll rolling, rolling or extrusion → detached → sizing (or reducing) cooling → straightening → ??hydrostatic test (or testing) logo → storage.
Hot-rolled seamless steel ingot casting can destroy tissue, grain refinement of steel and eliminate defects microstructure, so that the steel dense tissue mechanical properties are improved. This improvement is mainly reflected in the direction along the rolling direction to a certain extent in the steel is no longer isotropic; pouring formed bubbles, cracks and loose, can be welded at a high temperature and pressure.
After hot-rolled seamless steel pipe round baked to go through the pressure puncher piercing. Generally more common punch is tapered roller punching machine, punching machine such high production efficiency, product quality, perforated expanding capacity, can be worn a variety of steel. After perforation, round tube has been three-roll rolling, rolling or extrusion. To squeeze off the pipe after sizing. Sizing mill into high-speed rotating cone drill through perforated steel embryo formed steel. Pipe inside diameter is determined by the outside diameter sizing mill drill length.
After sizing the pipe into the cooling tower through spray cooling pipe after cooling, it is necessary to be straightened. After straightening the steel conveyor belt to the metal detection machine (or pressure test) for internal testing. If the internal pipe cracks, bubbles and other issues, will be detected. After the selection of steel but also through strict quality control manual. After the steel quality, spray paint on number, size, batch number and so on. By a crane into the warehouse.
Extrusion Production Process of Precision Seamless Pipe

Precision seamless steel tubes with conventional technology for the furnace + ESR -> forging or forging billet and rolling way. Product shape round bar, square flat and forgings. Then steam turbine plant for further processing, but the processing process more special shape, metal utilization after processing about 30%. To squeeze mode after production, will have the following advantages:
1, Precision seamless steel tubes in the best state of stress in the hot extrusion process, reducing the product of internal defects.
2, Easy to implement diverse cross-sectional shape, adapt more variety, small batch production.
3, In each direction of performance uniformity.
The main way to produce extrusion process: EAF + ESR -> forging or rolling cogging -> induction heating -> Extrusion -> annealing.
Extrusion and forging, rolling approach is the difference between:
1, Precision seamless extrusion heating temperatures than forging, rolling production is higher 30-60 ℃;
2, Deformation, high speed (deformed steel requires only 2-4S).
3, Multi-step, high metal consumption.
20# Precision Seamless Steel Pipe

The production process of precision seamless steel pipe includes cold drawing, hot rolling and thermal expansion. The main processing procedures are blank sawing process, ring furnace heating process, perforation process, rolling process, sizing process, cooling bed process, straightening process, pipe soot blowing process, magnetic flux leakage process, surface inspection and length measurement.
20# cold drawn seamless steel pipe is a common kind of steel products.  The length of exporting 20# cold drawn steel pipe generally can not exceed six meters, which is determined by the size of the container. It is mainly used for some mechanical parts, mechanical structure tubes.
20# hot rolling seamless steel pipe mainly refers to carbon content of the material, about 0.2% or so. This material, compared to other excellent carbon steel, is also common. It is commonly used for manufacturing seamless steel pipe, mould, high quality carbon steel plate, channel steel and other steel.
Though precision seamless steel pipe has good performance, it does not mean that it is powerful. However, seamless steel pipe can not be used under high temperature, humid environment, especially in the bad weather for a long time, which will reduce its lifespan. So in the use of seamless steel pipe, these premises should be paid special attention.

Compared to other solid steel material, seamless steel pipe is lighter with the same flexural torsional strength. It is an economic section of steel, widely used in the manufacture of structural and mechanical parts. Precision seamless steel pipe also has some of their own characteristics. They have been widely used to manufacture ring parts, can improve the utilization of materials, simplify the manufacturing process, save materials and processing time, such as rolling bearing rings, jack sets.
Generally, the industry require a higher precision, they often use precision seamless steel pipe, others mainly use seamless steel pipe if there is no precision requirements. After all, the price of precision seamless steel pipe is higher.
Why the current price of precision seamless steel pipe will be improved?
China’s steel production has increased, but the market demand for steel is too large, resulting in steel demand. And steel is the main material for the production of precision seamless steel pipe, steel shortage led to the shortage of precision seamless steel pipe, we know that the market demand for precision seamless steel pipe is increasing, and in this case, the price also increased. There are many different types of precision seamless steel pipe. Tthe materials are also different, such as 10#, 20#, 35#, 45#, 16Mn, 20Cr, 40Cr, Gcr15 and so on. Different types are required, therefore, there will be a type of precision pipe inevitably tube out of storage in a specific period of time, which makes the price increase.
From a certain point of view, if the market supply of precision pipe can meet the actual market demand, then the price will not be high. With the mature of precision pipe industry, the quality also need improve and become much more strict, many enterprises have to improve the production process and production technology. This is an increase in the production cost of the pipes. Therefore, the increase of added value leads to higher price.

How to get high quality precision seamless pipe?

If you are ready to get high quality precision seamless pipes then you have to believe the trusted manufacturer who have been in the industry for years. Yaang is one of the popular brand and they offer different types of precision seamless pipes which will surely meet the customer needs. Also we are the largest precision seamless steel pipes manufacturer in Asia.

1.The folding is easy to happen with inferior precision seamless tube
Folding is formed on the surface of the pipe line, this kind of defect often throughout the entire product longitudinal. The reason for causing of fold is due to the pursuit of high efficiency, large reduction of the inferior manufacturer, when go on the next rolling, the folding happens, and the folding products will be cracking after bending, and the strength of steel will decreased.
2. The inferior precision seamless tube has pitted surface
Pits is due to the defects of the irregular uneven steel surface caused by the worn groove. Because of the pursuit of profit, the inferior precision seamless pipe manufacturer often appear the overweight groove rolling.
3. The inferior precision seamless tube surface are prone to scarring
For two reasons: (1) the inferior precision seamless pipe material uneven with impurities. (2). The inferior material manufacturer with simple equipment which is easy to stick steel, these impurities after the roll bite are prone to scarring.
4. The surface of the inferior material is easy to have crack for the reason that it’s blank is adobe, and in the process of cooling due to the effect of thermal stress, cracks, after rolling, there is crack.
5. The inferior precision seamless pipe is easy to scratch for the reason that the inferior precision seamless pipe factory has simple equipment which is easy to produce burr and scratch steel surfaces. The deep scratches will reduce the strength of the steel.
6. The inferior precision seamless tube has no metallic luster, it is reddish or similar to the color of the pig iron for its original material is adobe. And the characteristics of precision seamless pipe cannot reach the required standard.
7. The transverse bar of the inferior precision seamless pipe is thin and low, and often appear phenomenon of discontent, because the manufacturers want to achieve big minus tolerance, finished product quality is not in accordance with the standard.
8. The cross-section of the inferior precision seamless tube is oval, because the factory in order to save material, the quantity of the finished product roll is big, the strength of rebar is greatly decreased, but also do not conform to the standard of rebar shape size.
9. The high quality steel composition is uniform, the cold shearing machine has high tonnage, and the cutting head end is smooth and neat, and the material of the inferior manufacturer is poor, cutting head end is not smooth or uneven, and also has no metallic luster.
10. The impurities of the inferior precision seamless pipe is very large, but the steel density is small, and the size out-of-tolerance is serious, so in the absence of vernier caliper, can be checked to weigh it.
11. The inner diameter of the inferior precision seamless pipe is volatile, the reason is: 1. the steel temperature is unstable; 2. the composition of steel is not uniform; 3. Because of the poorly equipped, and low foundation strength, there will be a larger changes within the same week, the steel bar caused by uneven on fracture.
12.The high quality tube logo and printing are specification.
13.The precision seamless pipe diameter more than 16, the spacing between the two trademark all over IM.
14.The inferior steel rebar longitudinal reinforcement often undulate.
15. The inferior precision seamless pipe manufacturer with no traffic, so the packing is loose.
Manufacturers who expertise in precision seamless pipe production are various. In these factories, their production ability is different, so the precision seamless pipe quality is also quite uneven. Some shoddy manufacturers who produce poor quality precision seamless pipe will mislead the decision of customers, which is shameful but can not be avoided. Then, how to distinguish the quality of precision seamless tube and square tube? How to choose suitable products with reasonable price? We should learn some basic knowledge about these question.
The pipe component distribution is very uniform for high quality precision seamless pipe and its surface is smooth and neat such as cold rolled precision seamless pipe. However, the precision seamless pipe whose quality is inferior has obvious folding mark on the surface, which can form a variety of folding line. The folding mark will affect the strength of precision seamless pipe seriously; it will become a potential safety issue afterwards. For inferior precision seamless tube, there are a lot of impurities in component, resulting in impure raw materials, which can cause uneven material easily. This kind of poor quality precision seamless pipe can not be applied in actual construction project.
Good quality precision seamless pipe has lots of excellent performances. For example, premium quality precision seamless pipe has very high strength which can not be scratched easily and light scratching is not obvious. However, inferior precision seamless pipe produced by a set of simple equipment will easily has burr that will lower precision seamless pipe strength. precision seamless pipe with metallic luster ranks high class in precision seamless pipe market, but inferior precision seamless pipe more or less has rugged dot which is caused by simple and crude production equipment. We should choose the precision seamless pipe with smooth surface without obvious burr.
The above basic points, generally can be used to judge the quality of precision seamless pipe. For all the precision seamless pipe manufacturers, each manufacturer has their own precision seamless pipe price in terms of their types or specifications. In the fluctuate precision seamless pipe market, choosing desirable products with good value is not an easy job. It is a time as well as energy commitment. Besides, we need to mater some related information in advance. Therefore, learning some judgment method of selecting is very important. If you have other questions about the select approaches, hope you can leave your messages below.

Source: China Precision Seamless Pipe Manufacturer – Yaang Pipe Industry Co., Limited (




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