K55 steel pipe

K55 steel pipe standard:
API SPEC 5CT - American Petroleum Institute Standard

Oil casing mainly produces steel pipe grades:
J55, K55, N80, L80, P110, etc.

K55 steel pipes are usually oil pipes, and the casings should be supplied with threads and couplings, or in the form of any of the following pipe ends:
Plain end, round thread without coupling or with coupling, partial trapezoidal thread with coupling or without coupling, direct connection type thread, special end processing, sealing ring structure.

Dimensional tolerance:

Type of steel pipe	Outer diameter (D)		Wall thickness (S)
Cold drawn tube	Steel pipe outer diameter (mm)	Allowable deviation (mm)	Allowable deviation (mm)
	＜114.3	±0.79	-12.50%

Oil pipes mechanical properties:

Standard	Grade	Tensile strength（MPa）	Yield Strength （MPa）	Elongation （％）	Hardness
API SPEC 5CT	J55	≥517	379～552
	K55	≥517	≥655
	N80	≥689	552～758
	L80(13Cr)	≥655	552～655		≤241HB
	P110	≥862	758～965

use:
Seamless steel pipes for oil well casing and tubing

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