Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, niobium, molybdenum, nickel, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 percent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60.
Different types of carbon steel pipes
Classes of carbon steel Carbon content %
Ultra-high carbon steel 1.00 – 2.00
High carbon steel 0.60 – 0.99
Medium carbon steel 0.30 – 0.59
Low carbon steel 0.16 – 0.29
Mild carbon steel 0.05 – 0.15
Black steel pipe is uncoated and made without steam, and therefore, it is widely used for transporting gas like propane and natural gas to residential and commercial building. Black steel pipe is manufactured as seamless pipe
which makes it a better type for gas transportation. It can be used for fire sprinkler system since it can prevent fire better than galvanized pipe. Since it has a dark color surface that is form by iron oxide during the manufacturing process, it is called black steel pipe.