Grades · Pipe & Tube Steel · API N80 Casing

API N80 Casing

Data verified

N80 is the mid-strength API 5CT casing and tubing grade for deeper wells beyond J55/K55 capability. Type Q (Q&T) is preferred where collapse resistance and uniform properties matter.

AISIAPI 5CT N80 (Type 1 / Q)
GBN80 (GB/T 19830)
CategoryPipe & Tube Steel

Chemical composition

ElementContent (%)
P≤0.030
S≤0.030
NoteType Q is quenched & tempered; Type 1 normalized — chemistry is mill practice

Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.

Properties

Yield strength552–758 MPa (80–110 ksi)
Tensile strength≥689 MPa (100 ksi)
Density7.85 g/cm³

Heat treatment

Type 1: normalized or normalized and tempered. Type Q: quenched and tempered for better collapse and consistency.

Equivalent grades

StandardDesignation
aisiAPI 5CT N80 (Type 1 / Q)
gbN80 (GB/T 19830)

Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.

Applications & Processing

Applications: Production casing and tubing, deeper intermediate strings.

Processing: Not for sour service — H2S environments require controlled-hardness grades such as L80/C90 per NACE MR0175.

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Source: API 5CT published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.