Why casing couplings stand alone
A casing coupling looks like a tubing coupling scaled up, but it is a different component, with its own specification basis.
Catalogue entries name the range concretely: BTC casing couplings in J55, K55, N80, L80 and P110 across the family; a 5-1/2 in casing coupling in BTC held as a stock item in the entry that anchors the coupling family; BTC and LTC stock couplings alongside J55 casing couplings; and a 13-3/8 in P110 BTC casing coupling listed in stock. Coupling stock sizes published by the company run from 1.315 in to 4-1/2 in for the tubing side.
Thread forms for casing couplings
| Form | Name | Form note |
|---|---|---|
| BTC | Buttress thread casing | Buttress form; the section it serves is named by the design |
| LTC | Long thread casing (long round) | Long round form; the section it serves is named by the design |
| STC | Short thread casing (short round) | Short round form; see the thread forms guide |
For ordering, state the coupling thread form, grade and size in full, as the design names them for the line. State the coupling specification in full on its own enquiry line, and ask for it to be restated in the quotation.
Finish, inspection and PSL
The process described on the company's coupling pages applies across the coupling families: phosphated internal and external surfaces, magnetic particle inspection, and marking in accordance with API Spec 5CT, with protective coating available on request and production processable to PSL1, PSL2 or PSL3. If your tally system needs a specific mark layout or colour banding by grade, put it in the RFQ as a quotation-stage instruction.
Packing options named by the company are cartons, wooden cases and pallets, or as agreed. Large casing couplings are heavy individual pieces; for sizes from 9-5/8 in upward, agree individual protection and lifting-friendly packing in the order rather than accepting a default bundle.
Should coupling grade always match pipe grade?
State both grades on the enquiry line — the pipe grade and the coupling grade your design names for it — and the quotation confirms the pairing for that line; where the design names different grades for pipe and coupling, name both in the enquiry, so the confirmed pairing is the designed one.
Is the 13-3/8 in P110 BTC coupling a stock item?
The catalogue lists it as a stock entry. Coupling stock moves with programmes, so current availability is confirmed in the written quotation before you build a rig schedule around it.
Can casing couplings be ordered without casing?
Yes, as an enquiry. Couplings are listed as an independent family, so an accessory-only enquiry can be sent on its own lines; the quotation confirms whether it can be accepted and in what scope. Repeat the full pipe specification — size, grade, thread form — on the coupling order so the couplings gauge to the string they will join.
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.