According to the production process, flat steels can be roughly divided into three types:

1. Hot Rolled Steel
2. Cold Rolled Steel
3. Coated Steel

1. Hot Rolled Steel

The rolling process begins by flattening slabs with rollers. This process is called Hot Rolling, and the product obtained is called Hot Rolled Coil (HRC) or simply Hot Rolled Steel. In the market, it is also frequently referred to as Black Steel.

When the scale layer on hot rolled coils is removed using acid, the resulting product is called Pickled Steel. Other terms include DKP, HRP, Acid Steel, or Pickled Steel. HRP stands for Hot Rolled Pickled.

Hot rolled steel is widely used in pipe and profile production.

2. Cold Rolled Steel

Hot rolled steel is generally produced at thicknesses of 2.0 mm or higher. For thinner sheets, hot rolled coils are processed via Cold Rolling, where the steel is passed through rollers at room temperature to reach the desired thickness.

The resulting product is called Cold Rolled Coil (CRC) or Cold Rolled Steel, often also referred to as Bright Steel. Cold rolled steel is widely used in the production of industrial pipes.

3. Coated Steel

Cold rolled steel can be coated for corrosion resistance. Common coatings include zinc (galvanized) or aluminum.

• Galvanized Steel: Coated using the hot-dip method, also called HDG Coil (Hot Dipped Galvanized). Technical specifications are often indicated with codes like DX51D+Z100, where “Z” indicates zinc coating and the number indicates the coating weight in grams per square meter per side.
• Aluminum-Coated Steel: Known in the market as Aluzinc (aluminum-zinc mix) or Alusi (aluminum-silicon mix). Codes like DX51D+AZ100 or DX52D+AS120 indicate the coating type and weight.

Coated steels are corrosion resistant and commonly used in the automotive industry, for example in exhaust pipes and automotive tubes.

Flat Steel – What is it? yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

Currently, fire suppression systems are almost mandatory in factories, parking lots, shopping centers, and residential complexes. These systems allow for automatic intervention when a fire starts, either extinguishing it or slowing its spread. As a result, the risk of damage and loss is minimized.

The proper functioning of fire suppression systems depends on their installation, with the most critical component being the fire protection piping system.

Importance of Fire Pipes

Fire pipes are a key component of fire protection systems. The steel pipes used must meet the technical requirements necessary for the building. Key criteria include:

• Pipe diameter and wall thickness must be calculated to withstand system pressure.
• Leak-proof performance must be guaranteed.
• Pipe connections must be accurate. For threaded or plain-end pipes, ends must be straight and smooth.
• Internal pipe surface must be smooth and free of burrs or debris.
• Pipes can be black, galvanized, or painted (varnished), but coatings must be smooth and free of rust for corrosion resistance.
• Fire pipes must have international safety certifications, such as UL (Underwriters Laboratories) and FM (Factory Mutual).

Borusan Fire Pipes – The Difference

Borusan Boru is the first manufacturer in Turkey to develop pipes specifically for fire protection systems. These pipes are known as Firesist Pipes.

Superior Features of Borusan Firesist Fire Protection Pipes:

Technical Features:

• FM approved
• UL/C-UL approved
• NSF certified
• Narrow wall thickness, straightness, and ovality tolerances
• CE, PED certified
• 100% leak-proof tested
• High-quality steel
• Galvanized or painted (black RAL 9005, red RAL 3000/3002/3009, gray RAL 7012)
• Plain-end, threaded, or grooved couplings
• Custom-length production available

Firesist Pipe Features:

• Manufactured according to EN 10217 & EN 10255 standards (light, medium, and heavy series available)
• Manufactured according to ASTM A53 & ASTM A795 standards (light, Sch7, Sch10, Sch30, Sch40, Sch80)
• Easy installation
• Saves labor, time, and cost
• Suitable for pressures exceeding 300 psi
• Red, black, and gray coating options
• Plain-end, grooved, and threaded coupling options
• Custom-length production available
• Precise tolerances
• Excellent ovality and straightness
• Internal burr-free products for grooved pipes 1” and above

Fire Protection Systems and Fire Pipes yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

• Inner weld protrusion (internal burr)
• Hardening of the steel during rolling
• Uneven mechanical properties in the pipe

SRM technology overcomes these disadvantages. In SRM production:

1. The pipe is initially produced at the largest possible diameter.
2. The internal burr is removed during welding.
3. The pipe is heated up to 900°C in a closed-system roller line.
4. It is then drawn to the final diameter and wall thickness, achieving a completely homogeneous structure with all internal stresses removed.

An SRM pipe entering the line at 90 mm diameter can be reduced to 21 mm, fully stress-relieved and softened.

Advantages of SRM Pipes

• Easily formable: Annealed pipes are highly suitable for bending.
• Seamless weld line: Weld seams disappear after drawing, preventing cracks or folding in tight bends.
• Smooth inner surface: Prevents scale accumulation.
• High corrosion resistance: Long service life.
• Small diameter, thick-walled pipes: Achievable where conventional welded pipes cannot, making SRM pipes competitive with seamless pipes.
• Cost-effective: SRM pipes are much cheaper than seamless pipes.

Applications of SRM Pipes

• Natural gas pipelines
• Boiler tubes
• Heat exchanger pipes
• Coil (serpentine) pipes
• General piping systems
• Couplings
• Elbows
• Automotive pipes

What is SRM Technology? yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

A good industrial pipe means high-quality raw material. It is easy to process and allows production with minimal waste. The strength and aesthetics—or overall quality—of the final product are directly influenced by the quality of the pipe.

While the price of an industrial pipe is an important factor when purchasing, the true cost is determined by its usage. A pipe that is not made from sheet metal suitable for bending, has a rough surface, or a wall thickness thinner than required may have a lower purchase price. However, once processing begins, the initial cost difference is more than compensated for by additional time, labor, and waste, making the cheap pipe more expensive in practice.

Borusan Industrial Pipes and Quality Difference
Borusan industrial pipes and profiles are manufactured according to EN 10305-2, EN 10305-3, and EN 10305-5 standards.

High-quality raw materials, primarily from Ereğli Demir Çelik (EDÇ), are used in production. Care is taken to ensure dimensional tolerances—such as outer diameter and wall thickness—are kept minimal.

• Surface defects such as scratches, dents, or roller marks are not allowed.
• Surface roughness is carefully controlled. Even the standard Borusan industrial pipe achieves satisfactory surface quality for chrome plating after slight polishing.
• For customers requiring extremely smooth surfaces, such as towel radiators and furniture manufacturers, Borusan offers polishing- and chrome-compatible production options.

During production, pipes undergo rigorous destructive testing under the most challenging conditions:

• Flattening test at 12 and 3 o’clock positions of the weld seam
• Expansion test (conical or cylindrical)
• Contraction test
• Bending test
• Tensile test (standard for all product groups)

Industrial Pipes yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

In 2019, Turkey’s total iron and steel exports amounted to 21,217,000 tons, with steel pipe exports accounting for 10% of this total.

Borusan Mannesmann Pipe exported 464,000 tons of steel pipes in 2019, representing 22% of Turkey’s total steel pipe exports and 24% of welded pipe exports.

Source: Turkish Steel Exporters’ Association (ÇİD) website and Borusan Mannesmann 2019 Annual Report

• ÇİD Statistics
• Borusan Mannesmann 2019 Annual Report

Turkey’s Steel Pipe Exports – 2019 yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

Based on the carbon content, carbon steels are classified into three categories:

1. Low Carbon Steel

Steels containing up to 0.30% carbon are called Low Carbon Steel or Mild Steel. This type of steel is commonly used in pipe and profile production.

2. Medium Carbon Steel

Steels containing 0.31% – 0.60% carbon are called Medium Carbon Steel. These steels also contain a certain amount of manganese (Mn). They are used in the production of machines, bolts, nuts, gears, transmission shafts, shovels, picks, and similar tools. They can be hardened through heat treatment.

3. High Carbon Steel

Steels containing 0.61% – 1.50% carbon are called High Carbon Steel. They are used to manufacture shafts, springs (spiral and leaf), scissors, bucket teeth, grader blades, high-strength machine parts, and handsaws. These steels are also suitable for hardening through heat treatment.

If you want, I can also make a simple table in English summarizing Low, Medium, and High Carbon Steel with their carbon content, common applications, and heat treatment suitability—perfect for a blog or catalog.

What is Carbon Steel? yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

Natural gas pipes are steel pipes specifically manufactured to safely transport natural gas to homes, workplaces, factories, hospitals, and other facilities.

Borusan Boru Doğal Gaz Borusu ve Üstün Özellikleri:

Arkon Çelik olarak bayisi olduğumuz Borusan Boru, dünyanın ve Türkiye’nin en kaliteli ve en güvenilir doğalgaz borusunu üretmektedir. Türkiye’nin ilk doğalgaz borusunu üretmiş ve yıllarca da tek üreticisi olmuştur. Sahip olduğu üstün SRM boru üretimi teknolojisi sayesinde de halen Türkiye’nin rakipsiz doğalgaz borusu üreticisi olmayı sürdürmektedir.

What is Natural Gas?

Natural gas is a fossil-based, colorless, odorless, and lighter-than-air combustible gas mixture consisting of methane, ethane, propane, butane, carbon dioxide, nitrogen, helium, and hydrogen sulfide. It is a petroleum derivative and ranks second in importance as a fuel after crude oil.

Natural gas can be hazardous due to explosion and suffocation risks. Explosions occur not from the gas cylinder itself but when leaked gas accumulates or ignites. While natural gas is non-toxic and does not contain carbon monoxide (so it does not block oxygen intake), it is lighter than air and accumulates near ceilings. Excessive accumulation can reduce oxygen levels and create a suffocation risk. This is why proper natural gas transmission and the use of high-quality natural gas pipes are critical.

The entire system transporting natural gas from its source to the end-user, including pipes, fittings, and equipment, is called a natural gas installation. During design, variables such as pressure drop and flow velocity are considered to determine pipe diameters and fitting specifications.

Borusan Natural Gas Pipes and Their Superior Features

As a distributor of Borusan Pipe, Arkon Çelik offers the world’s and Turkey’s most reliable and highest-quality natural gas pipes. Borusan produced Turkey’s first natural gas pipes and was the sole manufacturer for many years. Thanks to its advanced SRM pipe production technology, Borusan continues to lead the market in high-quality natural gas pipe production.

Material Quality in Borusan Natural Gas and Oil Pipes
The steel used for natural gas pipes must be free from double layering (lamination) and non-metallic inclusions. Inclusions can negatively affect weld quality during production and installation, while laminations can thin the pipe wall. The raw material must also have low impurity levels (phosphorus and sulfur), as impurities can react with chemicals in natural gas and accelerate corrosion.

Borusan Natural Gas Pipes are manufactured using high-quality materials tested to strict standards, ensuring safety for both life and property. They are easy to weld and thread, saving labor, time, and material. Borusan natural gas pipes comply with ISO 3183 (EN 10208-2) and API 5L standards.

Inner Surface Smoothness

Natural gas must flow smoothly without turbulence. During longitudinal seam welding, an internal weld bead (internal burr) forms along the pipe. To minimize risk, these burrs are removed to ensure a continuous cross-section for smooth gas flow. If burrs remain, gas flow can be disrupted, causing turbulence, pressure fluctuations, accelerated corrosion, and potential damage to devices such as valves and regulators.

Normalization of Borusan Natural Gas Pipes

In ERW (Electric Resistance Welded) pipe production, steel coils are shaped into a pipe form and welded using high-current electric resistance. Both cold forming and high-heat welding introduce varying internal stresses and microstructures in the pipe body and weld seam. Normalization is a heat treatment process in which the entire pipe is heated to 900°C and then cooled under controlled conditions to eliminate stress differences and achieve a uniform microstructure.

All Borusan natural gas pipes from 1/2″ to 3″ undergo normalization using Borusan’s exclusive SRM (hot drawing) technology. Benefits include:

• Elimination of internal stresses, resulting in a more flexible pipe
• Removal of hardness differences in the weld area
• Improved corrosion resistance (prevents galvanic corrosion)
• Enhanced cold-forming ability for bending

Note: Galvanic Corrosion (Electrochemical Corrosion) occurs when metals with different compositions create an electron flow. In welded pipes, the ferritic weld and heat-affected fine-grained perlitic zone act as anode (+) and cathode (-), causing corrosion. Borusan’s SRM process eliminates structural differences by heat-treating the entire pipe at a minimum of 900°C.

Natural Gas Pipes yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

1. Longitudinally Welded Pipe / ERW Pipe

Resistance Welded Pipe.

What is ERW? Electric Resistance Welding is a process in which the metal parts in contact are heated with an electric current, causing the metal to melt and permanently join. During pipe production, the two ends of flat steel are formed into a circular shape by rollers in the pipe mill. At the exact point where the edges meet, an electric current is applied to heat and fuse them together, creating a welded seam.

Borusan Mannesmann produces steel pipes using the ERW method for a variety of purposes, including water pipes, natural gas pipes, fire protection pipes, industrial pipes, construction pipes, automotive pipes, and main pipelines.

Longitudinally welded pipes are produced in diameters ranging from 5 mm to 350 mm.

2. Spiral Welded Pipe / SAW Pipe (HSAW or SSAW Steel Pipe)

For large-diameter pipelines used in projects like oil pipelines, water pipelines, and natural gas pipelines, the spiral welded pipe production method is used. In this method, the weld spirals around the pipe, which is why these are called Spiral Welded Steel Pipes.

The welding method used is Submerged Arc Welding (SAW). Since SAW only indicates the welding method and not the visual appearance of the weld, the more precise terms for spiral welded steel pipes are SSAW (Spiral Submerged Arc Welding Pipe) or HSAW (Helical Submerged Arc Welding Pipe).

What is Submerged Arc Welding (SAW)? In this method, a welding electrode is used along with an electric current to join the metal. Unlike the ERW process, which relies solely on electric current, SAW requires the electrode because rollers are not used in the same way during production.

Spiral welded pipes are produced in diameters ranging from 400 mm to 3000 mm, with wall thicknesses up to 25 mm, depending on the diameter.

Welded Pipes yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

The strength of steel is determined through mechanical properties, which are obtained by applying standardized tests to the material. For steel pipe production, the mechanical properties of the material are crucial. The right steel material must be chosen as the pipe raw material depending on the intended use of the pipe. For example, in steel constructions, in addition to the pipe dimensions, the material properties must be clearly defined according to the load the pipes will carry.

These tests provide three critical values:

Yield Strength
During a tensile test, the force applied to the material eventually moves it from elastic behavior to permanent deformation. This point is called the yield point. If the force is removed before reaching this point, the material returns to its original shape. The force measured at this point represents the steel’s yield strength. It is expressed in Newtons per square millimeter (N/mm²).

Tensile Strength
During a tensile test, the material stretches until it eventually breaks. The stress value at the moment of fracture is the ultimate tensile strength (maximum tensile stress). It is also expressed in Newtons per square millimeter (N/mm²).

Elongation
Elongation is defined as the maximum permanent increase in length of the tensile specimen. It is expressed as a percentage (%).

About Steel Strength yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

Iron, in its natural state, is a soft material and is also prone to corrosion. Therefore, steel—a strong and durable material—is formed as an alloy of iron with carbon and sometimes other elements.

What elements are in steel?

The main elements found in steel include:

• Carbon (C)
• Manganese (Mn)
• Silicon (Si)
• Phosphorus (P)
• Sulfur (S)
• Chromium (Cr)
• Nickel (Ni)
• Molybdenum (Mo)
• Titanium (Ti)
• Aluminum (Al)

Steel is classified based on its composition or content as follows:

• Carbon Steel
• Alloy Steel
• Stainless Steel

In our upcoming blog posts, you will find more detailed information on this topic.

What is Steel? yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

How accurately are pipes sold and used in the market? For example, it used to be very common to install galvanized water pipes for natural gas lines. Perhaps 15 years ago, this was not taken very seriously, but even back then, compliance with standards was essential.

Standards ensure safety, are impartial, and are not open to debate. They ensure the correct product is manufactured and used in the right place. That’s why standards are so important.

Always ask what type of pipe you are using, which standard it meets, and request its certificate.

Steel pipe norms can seem complex to many of us. Understanding an entire standard at once is not easy, especially since standards differ for water pipes, natural gas pipes, construction pipes, and industrial pipes.

But there’s no need to panic 🙂. With the simple information we’re sharing, you can easily check if a pipe meets standards.

By following these 3 steps, you can verify approximately 95% of a pipe’s compliance:

1. Visual inspection
2. Measuring the pipe dimensions (diameter, wall thickness, and length)
3. Checking the product certificate

Let’s go over these briefly:

1. Visual inspection:

• What does the pipe look like externally? Are there rust, dents, or deformations?
• Is the pipe straight or bent?
• How are the pipe ends? If beveled, is the bevel correct? If threaded, are the threads properly formed?
• Does it have a coupling? If coated, is the coating intact?
• Is the pipe round or oddly oval?
• How is the internal surface? Any broken burrs or debris inside? Any rust?
• Is the stencil on the pipe legible? The stencil should show the pipe brand, size, type, production standard, and material grade clearly.

2. Measuring pipe dimensions (diameter, wall thickness, and length):

• Use a caliper to measure the pipe’s outer diameter. While digital calipers are convenient, their precision may be insufficient. Preferably, use regularly calibrated mechanical calipers.
• Use a calibrated micrometer to measure wall thickness. Wall thickness measurement is the most critical measurement and should never be done with a caliper or ruler.
• Use a tape measure or ruler to check the pipe length. Since diameter and wall thickness require high precision, rulers or tape measures should not be used for these measurements.

For detailed instructions on measuring pipe diameter and wall thickness with calipers and micrometers, check our blog post [here].

3. Requesting and checking the pipe certificate:

• The product certificate guarantees the quality of the pipe. Always request the certificate from the supplier. It serves as the pipe’s identity and provides traceability.
• When the pipe label is unavailable, this document provides essential information.

A typical pipe certificate includes:

• Pipe diameter, wall thickness, and length
• Production standard
• Material grade
• Customer receiving the shipment
• Delivery note number and date
• Steel casting number and chemical composition
• Mechanical properties of the pipe (tensile strength, yield strength, and elongation)

We are sharing an example certificate for Borusan Pipe products below.

How to Check If Pipes Comply with Standards yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.

To theoretically calculate the weight of 1 meter of a steel pipe, all you need to know are the outer diameter and wall thickness, both in millimeters (mm).

The calculation is straightforward:

1. Subtract the wall thickness from the outer diameter,
2. Multiply the result by the wall thickness,
3. Then divide that number by 40.55.

That’s it!

Formula:

Where:

• D = Outer diameter (mm)
• t = Wall thickness (mm)

Example Calculation

Let’s calculate the theoretical weight of 1 meter of a 1-inch black steel water pipe.

For a 1” (1 inch) black steel water pipe,

• Outer diameter (D): 33.7 mm
• Wall thickness (t): 3.2 mm

Substitute into the formula:

The value obtained represents the theoretical weight, meaning that in actual production, small variations may occur within the tolerances allowed by pipe manufacturing standards. Therefore, the actual weight may differ slightly from the theoretical value.

Pipe Weight Calculation yazısı ilk önce Arkon Çelik üzerinde ortaya çıktı.