What API 5CT governs
API Spec 5CT — casing and tubing — defines the dimensions, steel grades, thread forms, gauging practice and inspection requirements for the pipe that lines and produces an oil or gas well. When a buyer writes a purchase order for 9-5/8 in N80 BTC casing, almost every word of that line is an API 5CT term: the size and weight tables, the grade chemistry and mechanical properties, the buttress thread form and its gauge, and the marking that must appear on each joint.
Two companion ideas matter. The company's coupling pages cite thread dimensions and tolerances to API Spec 5CT and 5B together. The PSL system names three product specification levels — PSL1, PSL2 and PSL3 — and the company's coupling literature states production can be processed to PSL1, PSL2 or PSL3. PSL is therefore an order field, not a marketing label: state the level in the enquiry, so the quotation confirms its scope for your order.
The factory range in API 5CT terms
| Element | Published range on this site |
|---|---|
| Casing sizes | 4-1/2 in to 20 in — fourteen listed sizes |
| Tubing sizes | 1.05 in to 3-1/2 in named; couplings stocked to 4-1/2 in |
| Carbon grades | J55, K55, N80-1, N80Q, L80-1, P110 |
| Chromium grades | L80-3Cr, 9Cr, 13Cr incl. P110-13Cr, 28Cr listed |
| Casing threads | STC, LTC, BTC plus premium gas-tight patterns |
| Tubing threads | EUE, NUE, special clearance combinations |
| Accessories | Couplings, pup joints, crossovers, premium processing |
J55 casing pipe and N80 casing pipe are both named catalogue entries.
Standards and certificates
Plainly and at system level. The company states that its products are manufactured and inspected in accordance with API Spec 5CT and that it operates under an ISO 9001 quality management system; its product pages use the same wording. No certificate number, no licence number and no issuing body is printed here, and certificates are available upon request. If your procurement system requires documentary verification before shortlisting, request the documents with your first enquiry — that is the correct sequence.
One boundary is worth stating. The company's published text states that it strictly executes API Spec 5CT — the company's own statement of the standard behind its casing and tubing lines. Drill pipe and line pipe are separate families: in the source catalogue both categories stand empty, and neither is offered on this site. Sucker rods are a separate family again — the source catalogue's sucker rod category page could not be retrieved when this catalogue was recorded, so the site holds no sucker rod record, and sucker rods are not offered here. What this site documents is the catalogue itself: 71 entries across its casing, tubing and accessory families.
What does PSL mean when I order couplings?
PSL is the product specification level — the three levels named in API Spec 5CT are PSL1, PSL2 and PSL3. The factory states coupling production to PSL1, PSL2 or PSL3; name the level in your order, and the quotation confirms the scope for that level.
Are thread dimensions to API 5B as well as 5CT?
The company's coupling pages state that thread dimensions and tolerances follow API Spec 5CT and 5B. Gauging practice follows the same pair of standards.
Can I see the API or ISO certificates?
Certificates are available upon request. Ask with your enquiry, and the quotation will state which documents are available for your specification; numbers are not published on the website.
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.