When comparing black iron pipes and black steel pipes, many buyers and purchasing engineers find these two terms confusing because they are often used interchangeably. What is the difference between black iron pipes and black steel pipes? It's actually quite easy to distinguish them. Black steel pipes generally refer to carbon steel pipes produced according to modern standards, possessing higher strength, more stable material properties, and better pressure resistance; while black iron pipes mostly refer to lower-grade steel or iron pipes used in earlier times, with inconsistent composition, poor corrosion resistance, and prone to rusting when used in water or humid environments for extended periods. Therefore, from the perspective of modern industrial and construction use, black steel pipes are the mainstream and more reliable choice, while black iron pipes are typically only found in older buildings or low-requirement scenarios.
What Do “Black Iron Pipe” and “Black Steel Pipe” Mean?
Black steel pipe
Black steel is made from steel that is not galvanized. It gets its name from the scaly, dark iron oxide coating on its surface. Because its surface is dark colored by iron oxide during the manufacturing process, it is called black steel pipe.Depending on the production process, black steel pipes are divided into two main types: seamless pipes and welded pipes. ASTM A53/A53M is a standard specification for pipe, steel, black and hot-dipped, zinc-coated, welded and seamless.
Black iron pipe
Black iron pipes are ordinary iron pipes without any surface treatment. Iron pipes are called black iron pipes before galvanizing, and they are called white iron pipes after galvanizing, also known as water and gas pipes.
Most homes built before the 1960s used black iron pipes for lines such as water and gas. It is a form of steel pipe but is made from a more malleable product.
Black iron pipe, it is actually a form of steel pipe, but its composition is slightly different and the material makes it more malleable. However, water does corrode this type of pipe quite easily compared to steel.
Black iron pipe VS black steel pipe
Construction is the main difference between the two products. Black iron pipes have seams and users can easily connect them to other pipes using connecting valves. Steel pipes are mostly used in industrial applications and require welding.
Black iron pipe is used to transport natural gas and propane gas in residential applications. Black steel pipes are seamlessly manufactured and have better fire resistance than galvanized pipes, making them more suitable for gas transmission and fire sprinkler systems.
Texture
The steel pipe is very delicate to the touch, almost cool to the touch. It won't scratch as easily as black iron pipe, but that doesn't mean it won't be damaged by a wrench or hammer while working around it. Black iron pipe has a rough, grainy texture and feels the same at room temperature. Black iron pipes will peel off if handled too much. However, both are easily heated and can burn the user's hands.
Repair
The main problem with black iron pipes - especially at home - is leakage at the connectors. Repairing these leaks requires a lot of work, which is why many people no longer use black iron pipes. Steel pipe does not have this problem because it is usually welded. However, it is more expensive than black iron pipe or PVC.
Cost
Steel pipe is typically around 20% more expensive than black iron pipe, but it does provide better resource savings in the long run by being more energy efficient. Its durability and cost are part of the reason for the growth in the use of steel pipe in large industrial operations in the United States. However, black iron pipe is more widely available than steel pipe, which also makes it more convenient.
Corrosion resistance differs
Black steel pipes are slightly better, but neither is suitable for long-term water supply; black iron pipes are more prone to rusting.
Applications differ
Black steel pipes are used for gas, fire protection, and structural support; black iron pipes are mostly found in older buildings or for light-duty applications.
Standards and stability
Black steel pipes have unified standards and high stability; black iron pipes have inconsistent material properties and greater application limitations.
FAQs
Is black steel pipe stronger than black iron pipe?
Yes. Black steel pipe is stronger and more durable.
Can black iron pipe be used for water lines?
Not recommended. It corrodes quickly when exposed to water.
What is the main difference between black steel and black iron?
Black steel is modern carbon steel with better strength and consistency; black iron refers to older, lower-grade material.
Further reading:
1.Detection method of black steel pipe
2.Maintenance of seamless black steel pipe
