Where J55 belongs in a well
J55 is one of the grades in the published API 5CT grade list, and a named catalogue entry for this factory. Which sections a design assigns to J55 is the design's decision, taken against each section's depth, pressure and collapse cases. J55 is not a substitute for another grade the design names; it is quoted as named, like every grade on this site.
J55 casing is a named catalogue entry for this factory, and J55 appears again where it matters for a complete order: J55 casing couplings are listed in the coupling family, including a J55 special-clearance tubing coupling entry held in stock on the tubing side. Pipe and couplings for a J55 programme are confirmed as a combination, not read off the lists: state the thread form the design names for each section — STC, LTC or BTC — with size and weight, and the quotation confirms whether that pipe-and-coupling line can be accepted.
Sizes and specification
J55 is named in the published grade list, and the casing sizes are published as a separate list — fourteen machinable sizes from 4-1/2 in to 20 in. The two lists are not documented against each other, so a J55 line at a given size is confirmed in the quotation rather than read off the lists. The full size list is on the casing pipe sizes page. Specify J55 by size, weight and thread in the RFQ; the size, weight and thread your design states — and ask for the full line to be restated in the quotation for checking against your well schematic.
| Decision | J55 guidance |
|---|---|
| String position | The sections the well design assigns to J55 |
| Thread | STC, LTC or BTC where the design states |
| Coupling grade | The grade the design names for the coupling line |
| Beyond J55 | Where the design names another grade for a section — see that grade's page |
J55 versus K55 — the honest comparison
J55 and K55 sit side by side in the standard as separate designations, and this site publishes no chemistry or consistency comparison between them. In this factory's published grade list both J55 and K55 appear, so the grade the tender names can be quoted as named. If your tender names K55, quote K55; if it names J55, a substitution is a design change, not a saving to assume — and any substitution should be documented in the quotation, never made silently in production.
One caution travels with any grade programme, J55 included: material from different orders stored together in one yard can be mixed, whatever the grades involved. Marking follows API 5CT practice. Ask for the marking layout to be stated in the quotation if your yard system depends on it.
Is J55 only for surface casing?
The design assigns sections to J55 against their depth, pressure and collapse cases; nothing in the grade name alone confines it to one string position. If your design names J55 for a section, it is quoted as named.
Can J55 casing be supplied with BTC threads?
BTC, LTC and STC are all listed thread forms for the casing family, and J55 is a listed grade — but the grade list and the thread list are not documented against each other, so the combination is confirmed line by line. State the form per line, with size and weight; the quotation confirms whether that grade-and-form line can be accepted.
What covers an interval the design does not assign to J55?
Whichever grade the design names for that interval. Send the interval data and ask for the grade your design names to be priced 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.