N80 in the published grade list
N80 casing pipe sits in the published API 5CT grade list, and is quoted for the intervals whose design names N80. The company's product data for its named 5 in N80 casing sample gives yield strength 552 to 758 MPa and tensile strength 689 MPa. Those figures are published for that sample.
The published grade list distinguishes N80-1 and N80Q. The distinction matters in procurement language: N80-1 is the standard normalised variant in common API practice, while the Q variant denotes quenched-and-tempered delivery with its own testing expectations. A tender specifies one or the other, and a quotation that simply says N80 without the variant is incomplete. When you enquire, copy the variant from your design exactly — N80-1 or N80Q — and ask for it to be restated in the quotation. The catalogue's anchor product for this page is the named 5 in N80 casing entry; N80 also appears across the coupling family, including N80 and L80 tubing couplings and an N80 BTC casing coupling presence in the family's grade spread.
Material and process notes from the factory data
The company's N80 casing page describes its material route as 36Mn2V micro-alloyed non-quenched-and-tempered steel with controlled temperature and controlled cooling processing — a vanadium micro-alloy approach to reaching N80 properties. That is the manufacturer's stated route for the named 5 in sample, and it belongs in a technical evaluation of that sample alongside its mechanical numbers. The same page places N80 inside the wider casing offer: hot-rolled production, sizes machinable from 4-1/2 in to 20 in, STC, LTC and BTC threads plus premium options, and packing by steel strap or steel frame or as agreed.
| Property / field | Company-published data — 5 in N80 sample |
|---|---|
| Yield strength | 552–758 MPa |
| Tensile strength | 689 MPa |
| Variants in grade list | N80-1, N80Q |
| Size envelope | Casing sizes 4-1/2 in to 20 in (family list) |
| Threads | STC, LTC, BTC and premium processing |
The published sample data states yield and tensile strength. Buyers building a technical file should ask for the mill data with the quotation rather than copying a web page.
Specifying N80 against a programme
An N80 line on an RFQ should carry size, weight, variant (N80-1 or N80Q), thread, length range and quantity, plus the PSL or documentation level the tender requires. Where one order carries several grades, keep each grade as its own line so threading slots, inspection and marking stay clean. State the coupling grade your design names on the enquiry line with the pipe line, and ask for it to be confirmed for that line in the quotation.
N80-1 or N80Q — which should I order?
Whichever your well design or tender names. The variants differ in heat-treatment route and testing expectations. If the design simply says N80, raise it at enquiry stage and the quotation will state the variant it prices.
How does N80 compare with L80?
They are different designations in the published list: L80-1 is the grade designs name for the sections they assign to it, and where your design sets a hardness limit it is stated in the enquiry and applied to the L80 line. For the CO2 case, also read the 13Cr page before deciding.
Is 5 in the only N80 size?
5 in N80 is the named catalogue anchor. N80-1 and N80Q are named in the published grade list and the sizes are published as a separate list; the two lists are not documented against each other, so give your size and weight and the combination is confirmed in the quotation.
Request a Quotation
Send your size, grade, thread and quantity. MOQ, packing and lead time are confirmed in the quotation for your exact specification — no generic promise replaces a written quote.