Casing and tubing

Standards and steel grades,
Tube sizes acc. to API 5CT.

Tubes for casing and tubing are manufactured using the hot rolling process. Semi-finished product used for these tubes is continuously cast blooms. Tubes for casing and tubing are used in the mining industry to obtain crude oil and natural gas. Tubes are made from carbon and alloyed steel. Overview of dimensional standards and technical-delivery conditions by which the tubes for casing and tubing are made and supplied are shown in separate overview.

Tubes for casing and tubing dimensions

Outside diameter of the tubes for casing and tubing ranges from 1.05 to 4.5 inches (26.67 to 114.30 mm), and wall thickness from 0.113 to 0.380 inches (2.87 to 9.65 mm). For details see the dimensional table. Preferably the tubes are supplied as hot rolled.

The types of steel for tubes for casing and tubing


Tubes for casing and tubing are made from the following steel, according to API 5CT H40, J55, K55 and N80. These together with its chemical composition and mechanical properties are shown in separate overview. Steel is made in the electric arc furnace and they are fully killed.

Delivery condition and tubes surface

Hot rolled tubes do not go through further thermal processing. Tubes surface corresponds to the way they were produced. Normal annealing (N) may be done after agreement.

Length of tubes for casing and tubing

(Values for Tubing – pumping tubes)
Group 1: 6.10–7.32 m (20–24 ft)
Group 2: 8.53–9.75 m (28–32 ft)
Group 3: 11.58–12.80 m (38–42 ft)
(Values for– tubes)
Group 1: 4.88–7.62 m (16–25 ft)
Group 2: 7.62–10.36 m (25–34 ft)
Group 3: 10.36–14.64 m (34–48 ft)

Dimensional tolerances of tubes for casing and tubing

D < 4 ½ inch = ±0.79 mm (±0.031 inch)
D ≥ 4 ½ inch = –0.5 % +1.0 % D
T = –12.5 % (+ limited by weight)
Weight (1 tube) = –3.5 % +6.5 %

Straightness

Tubes are visually straight.

Ends of tubes

Ends are smooth, without swaging, threads and without flanges.

Oil pipe and bundle marking

- stamp marking
- stencil marking of the agreed data
- color bands
Bundles are marked with metal tag with required information

Surface protection for oil tubes

The pipes are supplied without temporary anticorrosion protection. Upon request the tubes may be plugged with plastic caps.

Tubes packaging

Tubes are bound with steel band into bundles with weight 1000–3500 kg. Bundle is bound with 4 steel bands.

Tubes testing

Tubes are tested according to requirements of API 5CT standard, eventually additional agreed tests possible when ordering the tubes.


Certified test reports for tubes for casing and tubing

API 5CT
EN 10204 – 3.1,
DIN 50049 – 3.1.B