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API Casing

Application: Used as the Structural Retainer for the Walls of Oil, Gas Wells

Specification: OD: 4 1/2’’ ~ 20’’ (114.3mm ~ 508mm)

                          WT: 0.205’’ ~ 0.635’’ (5.21mm ~ 16.13mm)

                          LENGTH: R1, R2, R3

Standard: API 5CT J 55/K55/N80/C75/L80/C90/T95/Q125

Process Type: Seamless (SMLS), Electric Resistance Welded (ERW)

End: Beveled, Square Cut, With LTC/STC/BTC/VAM Connection

Surface: Anti-corrosion Water Based Paint

Packing: Protection Caps in Both Ends, Waterproof Paper Wrapped, Two Tags

               

Tolerance

Types of steel tubes
Outer Diameter
Wall Thickness
Cold-rolled tubes
Tube sizes(mm)
Tolerances(mm)
Tolerances(mm)
<114.3
±0.79
-12.5%

Chemical Composition

Standard Grade Chemical compositions(%)
API SPEC 5CT
J55
C Si Mn P S Cr Ni Cu Mo V
K55 0.34~0.39
0.20~0.35
1.25~1.50
≤0.020
≤0.015
≤0.15
≤0.20
≤0.20
/ /
N80
0.34~0.38
0.20~0.35
1.45~1.70
≤0.020
≤0.015
≤0.15
/ / / 0.11~0.16
L80
0.15~0.22
≤1.00
0.25~1.00
≤0.020
≤0.010
12.0~14.0
≤0.20
≤0.20
/ /
P110
0.26~0.395
0.17~0.37
0.40~0.70
≤0.020
≤0.010
0.80~1.10
≤0.20
≤0.20
0.15~0.25
≤0.08

Mechanical Properties

Grade Type Total elongation under load (%)
Yield strength (min)
Yield strength (max)
Tensile strength min Mpa
Hardness Max (HRC)
Hardness Max(HBW)
J55 - 0.5
379 552 517 - -
K55 - 0.5
379 552 655 - -
N80 1 0.5
552 758 689 - -
N80 Q 0.5
552 758 689 - -
L80 1 0.5
552 655 655 23 241
L80
9Cr 0.5
552 655 655 23 241
L80
13Cr 0.5
552 655 655 23 241
C90 - 0.5
621 724 689 25.4 255
C95 - 0.5
655 758 724 - -
T95 - 0.5 655 758 724 25.4 255
P110 - 0.6 758 965 862 - -
Q125 All 0.65 862 1034 931 - -