Seamless Steel Drilling Pipe API N80 Casing Pipe Standard:J55,K55,N80,P110

Oil Tube & Casing Size & Specification

Specifications: diameter: 320 to 127 mm thickness: 0.4 to 12.7 mm Length: 6 m above, and, in accordance with customer demand, supply and other specifications of steel pipe

Casing is a large-diameter pipe that serves as the structural retainer for the walls of oil and gas wells, or well bore. It is inserted into a well bore and cemented in place to protect both subsurface formations and the wellbore from collapsing and to allow drilling fluid to circulate and extraction to take place. Steel Casing Pipes have smooth wall & minimum yield strength of 35,000 psi.

Tubing: Tubing is pipe used for the transportation of crude oil and natural gas from an oil or gas layer to the surface after drilling is complete. It is made to withstand the pressure generated from the extraction process. Tubing is manufactured in the same way as casing, except that an additional process known as "upsetting" is applied to thicken the pipes.
•Process: ERW and Seamless
•Standard: API 5CT
•Certificate: Casing: LTC, STC, BTC, VAM.Tubing: NUE, EUE.
•Out Diameter: Casing: OD 4 1/2"- 20" (114.3mm-508mm)   Tubing: OD 2 3/8" - 4 1/2" (60.3mm-114.30mm)

•Wall Thickness: 0. 205"- 0.635"  •Length: R1(4.88mtr-7.62mtr), R2(7.62mtr-10.36mtr), R3(10.36mtr or longer)

•Steel Grade: H-40, J55, K-55, N-80, C-75, L-80, C-90, T-95, Q-125

•Surface: Corrosion proofing water based paint

•End: Beveled, Square cut. And pipe protection cap especially for casing and tubing.

•Heat treatment: Normalized, Quencher+Temper

Oil Tube & Casing Transport / Freight


We firstly possess a perfectly developed transport by which we can deliver goods directly from the warehouse to the customer. Secondly, we direct traffic, which ensures a delivery from the factory to customers from 15 tons. Oil Tube & Casing that are not in stock at our own warehouse are based on the star traffic from other sites - every day! We aim at providing professional customer service with one-stop purchasing, along with superior quality control, competitive price, fast lead time and convenient transportation.

Oil Tube & Casing Marking & Packaging
Packaging is an integral part of the product. It guarantees that the Oil Tube & Casing is delivered to the customer in the required quality. For smaller orders the size of the Oil Tube & Casing bundle depends on the no. of Tubes ordered, for larger orders the tubes are packed into individual bundles and in such a way that the maximum weight of 4000kg per bundle is not excedded. Bundle tied down with steel tape. Bundle tied down by steel strap underlaid by tapaten.

We can also provide Oil Tube & Casing wooden box packing, cardboard boxes, plastic wrapping, using hardened paper with PE meshing (used as protection against mechanical damages of tubes), into tapaten and polyethylene sheet etc.

While marking we choose a specific item number as well different color shade to differentiate steel grades. We mark Oil Tube & Casing as needed with the most suitable & visible marking technique

Carbon Steel :A53 Gr B / A106 Gr B / API 5L Gr B to Gr X 70

                   Low Temperature Pipes  A333 Gr 3 and Gr 6

                  Stainless Steel & Special Stainess Steel :A312 / SA 312 TP 304/304L, 316/316L, 

                  310, 317, 321, 347, 410, 904, H Grades

                 Alloys Steel  :A335 Gr. P5 / P9 / P11 / P 22 / P91 & P92

                Special Alloys   Nickel Alloys

            Nickel 200/201 - B161 - UNS N02200/N02201        Alloy 400 - B165 - UNS N04400 - Monel® 400

           Alloy 600 - B167- UNS N06600 - Inconel® 600          Alloy 625 - B705 - UNS N06625 - Inconel® 625
           Alloy 800H/800HT - B407 - UNS N08810/N08811 - Incoloy® 800H/HT
           Alloy 825 - B423 - UNS N08825 - Incoloy® 825
          Alloy 276 - B622 - UNS N10276 - Hastelloy® C-276

2. Size: 1/2''----48''

3. Standard: ANSI , JIS , DIN , GOST , EN , 

4. Certification: ISO9001, SGS, CTI, ROHS

5: Detailed information 

OK Fitting offers a wide-range of carbon steel pipe products. The term carbon steel pipe can be used to describe a wide range of metal tubular goods whose main alloying element is carbon in a range of 0.12%-2%. Apart from carbon elements like chromium, cobalt, molybdenum, nickel, niobium, titanium, tungsten, vanadium & zirconium can be added to attain respective alloying effect.



For an example A333 grade 6 pipe has high tensile strength and impact properties used at low temperatures application as compared to A106 Grade B pipe with low tensile strength and used at room temperatures or higher temperatures. This is achieved by addition of manganese above the 0.9%, which is limited to 0.65% in A106 pipe.



In general, a pipe is referred as a carbon steel pipe when the maximum specified content of Manganese – 1.65%, Silicon – 0.6% & copper 0.6 % does not exceed the limit prescribed.



Carbon steel pipe are further divided into four categories:

Low carbon steel pipe – Carbon content 0.55-1.05%

Medium carbon steel pipe- Carbon content 0.25-10.6%

High carbon steel pipe- Carbon content 0.9-2.5%

Super High carbon steel pipe- Carbon content 2.5-3.0%

As the Carbon content increases, high carbon steel pipe can become harder and stronger by quenching and tempering with lower ductility.High carbon steel pipe if not heat treated, may result into low weld ability & low melting point.Large diameter pipe used for water transportation and general transit are made of carbon steel.



Depending on the manufacturing method these pipe are divided in 3 different types.

Seamless pipe – pipe formed by passing hot steel through a die to get the shape of a pipe. Carbon steel seamless pipe are manufactured up to a range of 24-(600NB). Though this is the most expensive method due to the machinery and time involved in manufacturing, this is the most reliable method ever invented.

Welded pipe– pipe formed by wrapping a steel sheet in a circular motion, which is then welded at the seam, are known as welded pipe. These pipe are highly in demand due to cheap pricing. Depending on type of requirement these pipe are welded in the following forms

a. ERW: Electro resistance welded pipe  b. EFW: Electro Fusion Welded pipe

c. SAW: Submerged Arc Welded pipe

Casting Mould pipe – The ancient and the oldest method of casting hot liquids.These pipe have a very less demand

Heat Treatment

Carbon Steel pipe can be heat treated in various ways as listed below.

Normalising  Annealing  Quenching  Quenching and Tempering  Austempering  Spherodizing

Ok Fitting  is a stockiest and supplier of Carbon steel pipe from China. With a size range of ½–24- in seamless pipe and ½–72- in welded pipe, we provide length variations from 4-7 meters as single random length and 7-13 meters as double random lengths. With black varnished finish and plain or beveled ends we provide cut to length pipe are per client-s requirements.Although many of the same manufacturing principles apply to both carbon steel pipe and various similar alloy tubular goods, the focus of this narrative will be on the manufacturing process of mild carbon steel pipe goods commonly used for oil and gas as well as water transmission, structural applications, general purpose casing, piling, and mechanical components.Carbon steel pipe produced in India are widely used worldwide including crucial markets like south Africa, Australia, Indonesia, Iran, Iraq, Nigeria and Canada.