Use this reference to separate line pipe from well casing, compare common mechanical requirements and prepare an accurate quotation request. Values are for preliminary engineering review; the applicable standard edition, purchase specification, heat-treatment condition and MTC govern final acceptance.
Updated 13 November 2026 · HEBEI HONGFENG IMPORT & EXPORT CO.,LTD
The correct product starts with what the pipe does in service, not with the grade abbreviation that looks familiar.
For oil, gas or water transmission and gathering. PSL1 provides the base specification level; PSL2 adds more controlled chemistry, mechanical limits and testing.
Casing stabilizes the wellbore and isolates formations. Tubing is the inner conduit for production or injection. Both require connection, length and service-condition review.
For power-plant steam lines, boiler tubes, refinery and high-temperature process service. Grade selection depends on design temperature, pressure, creep duty and welding.
Substitution warning: API 5L line pipe must not be sold or described as API 5CT casing merely because the dimensions are similar. Standard scope, threading, marking, inspection and design requirements differ.
PSL1 states minimum yield and tensile requirements for the pipe body and weld. It does not impose the same mandatory maximum yield or full PSL2 chemistry framework shown in the next section.
| Grade | Min. yield Rt0.5 (MPa) | Min. tensile Rm (MPa) | Min. weld tensile (MPa) |
|---|---|---|---|
| L175 / A25 | 175 | 310 | 310 |
| L175P / A25P | 175 | 310 | 310 |
| L210 / A | 210 | 335 | 335 |
| L245R/BR or L245/B | 245 | 415 | 415 |
| L290R/X42R or L290/X42 | 290 | 415 | 415 |
| L320 / X46 | 320 | 435 | 435 |
| L360 / X52 | 360 | 460 | 460 |
| L390 / X56 | 390 | 490 | 490 |
| L415 / X60 | 415 | 520 | 520 |
| L450 / X65 | 450 | 535 | 535 |
| L485 / X70 | 485 | 570 | 570 |
Elongation: PSL1 uses the API formula A_f = C · A_xc^0.2 / U^0.9. A single percentage should not be substituted for the calculated requirement. Intermediate grades and product-analysis limits also follow the full standard.
PSL2 controls both minimum and maximum yield strength, minimum and maximum tensile strength, and the maximum yield-to-tensile ratio. The delivery-condition suffix is part of the grade definition.
| Grade | Yield min–max (MPa) | Tensile min–max (MPa) | Max. Rt0.5/Rm |
|---|---|---|---|
| L245 / B | 245–450 | 415–760 | 0.93 |
| L290 / X42 | 290–495 | 415–760 | 0.93 |
| L320 / X46 | 320–525 | 435–760 | 0.93 |
| L360 / X52 | 360–530 | 460–760 | 0.93 |
| L390 / X56 | 390–545 | 490–760 | 0.93 |
| L415 / X60 | 415–565 | 520–760 | 0.93 |
| L450 / X65 | 450–600 | 535–760 | 0.93 |
| L485 / X70 | 485–635 | 570–760 | 0.93 |
| L555 / X80 | 555–705 | 625–825 | 0.93 |
| L625 / X90 | 625–775 | 695–915 | 0.95 |
| L690 / X100 | 690–840 | 760–990 | 0.97 |
| L830 / X120 | 830–1050 | 915–1145 | 0.99 |
Read with the suffix: R = as-rolled, N = normalized, Q = quenched and tempered, and M = thermomechanically rolled. M is associated with welded product and should not be presented as a seamless-pipe delivery condition.
The following values are maximum mass fractions from the seamless-pipe portion of the PSL2 chemistry table. They are a screening reference, not the full purchase specification.
| Grade / condition | C | Si | Mn | P | S | CEIIW | CEpcm |
|---|---|---|---|---|---|---|---|
| L245R/BR · L245N/BN | 0.24 | 0.40 | 1.20 | 0.025 | 0.015 | 0.43 | 0.25 |
| L290R/X42R · L290N/X42N | 0.24 | 0.40 | 1.20 | 0.025 | 0.015 | 0.43 | 0.25 |
| L360N / X52N | 0.24 | 0.45 | 1.40 | 0.025 | 0.015 | 0.43 | 0.25 |
| L390N / X56N | 0.24 | 0.45 | 1.40 | 0.025 | 0.015 | 0.43 | 0.25 |
| L415N / X60N | 0.24 | 0.45 | 1.40 | 0.025 | 0.015 | As agreed | |
| L245Q / BQ | 0.18 | 0.45 | 1.40 | 0.025 | 0.015 | 0.43 | 0.25 |
| L360Q / X52Q | 0.18 | 0.45 | 1.50 | 0.025 | 0.015 | 0.43 | 0.25 |
| L390Q / X56Q | 0.18 | 0.45 | 1.50 | 0.025 | 0.015 | 0.43 | 0.25 |
| L415Q / X60Q | 0.18 | 0.45 | 1.70 | 0.025 | 0.015 | 0.43 | 0.25 |
| L450Q / X65Q | 0.18 | 0.45 | 1.70 | 0.025 | 0.015 | 0.43 | 0.25 |
| L485Q / X70Q | 0.18 | 0.45 | 1.80 | 0.025 | 0.015 | 0.43 | 0.25 |
| L555Q / X80Q | 0.18 | 0.45 | 1.90 | 0.025 | 0.015 | As agreed | |
Full-table conditions still apply: V, Nb, Ti, Cu, Ni, Cr, Mo and B limits, the carbon-to-manganese adjustment rule, the Nb+V+Ti total, t > 20 mm carbon-equivalent agreements and product analysis tolerances must be taken from the applicable standard and purchase specification.
A single “PSL2 impact value” is technically incomplete. The minimum full-size CVN absorbed energy changes across grade bands and outside-diameter ranges.
| OD D (mm) | ≤X60 | >X60–≤X65 | >X65–≤X70 | >X70–≤X80 | >X80–≤X90 | >X90–≤X100 | >X100–≤X120 |
|---|---|---|---|---|---|---|---|
| ≤508 | 27 | 27 | 27 | 40 | 40 | 40 | 40 |
| >508–≤762 | 27 | 27 | 27 | 27 | 40 | 40 | 40 |
| >762–≤914 | 40 | 40 | 40 | 40 | 40 | 54 | 54 |
| >914–≤1219 | 40 | 40 | 40 | 40 | 40 | 54 | 68 |
| >1219–≤1422 | 40 | 54 | 54 | 54 | 54 | 68 | 81 |
| >1422–≤2134 | 40 | 54 | 68 | 68 | 81 | 95 | 108 |
Do not quote by grade alone: PSL2 purchase requirements can add a specified test temperature, subsize conversion, weld/HAZ testing, drop-weight tear testing or fracture-arrest requirements. All must be explicit in the inquiry.
| OD D (mm) | Except pipe end | Pipe end |
|---|---|---|
| <60.3 | −0.8 to +0.4 mm | −0.4 to +1.6 mm |
| ≥60.3–≤168.3 | ±0.75%D | ±0.5%D, max ±1.6 mm |
| >168.3–≤610 | ±0.75%D | ±0.5%D, max ±1.6 mm |
| >610–≤1422 | ±1%D | ±2.0 mm |
| >1422 | By agreement | By agreement |
The tolerance table applies to seamless pipe at t ≤25.0 mm; greater wall thickness is by agreement. For D ≥219.1 mm, the standard permits dimensional verification through calculated inside diameter or measured inside diameter under stated conditions.
Grade symbols alone do not define a complete casing order. Product specification level, heat treatment, dimensions, weight, length range, coupling, thread and service environment also control suitability.
| Grade | Yield strength (MPa) | Min. tensile (MPa) | Engineering note |
|---|---|---|---|
| J55 | 379–552 | 517 | Common basic casing reference; confirm specification level and connection. |
| K55 | 379–552 | 655 | Higher minimum tensile than J55; confirm application and product form. |
| N80 / N80-1 / N80Q | 552–758 | 689 | The suffix and heat treatment matter; do not assume sour-service suitability. |
| L80 / L80-1 / L80Q | 552–655 | 655 | Hardness and sulfide-stress-cracking controls require project assessment. |
| P110 | 758–965 | 862 | High-strength casing reference; not a default sour-service grade. |
Connection and service: STC, LTC and BTC are common API connections; premium or gas-tight connections follow the project. Casing and tubing requiring H2S, CO2, low-temperature or high-collapse service need formal engineering review.
Grade pages: K55 · N80 · L80 · P110 · Redacted K55 MTC sample
Casing stabilizes the wellbore, isolates formations, supports the wellhead and provides the path for subsequent operations. Common sizes are approximately 4-1/2 to 20 inches, with R1, R2 or R3 length ranges.
Tubing is the inner production or injection conduit. Common sizes are approximately 1.050 to 4-1/2 inches. EUE, NUE or premium connections are selected with the completion design.
A drawing, line list or purchase order can replace a written list. These are the fields used to check the material route, testing and packing.
HONGFENG will verify the requested API 5L or API 5CT combination, confirm the available delivery route and quote with the inspection documents stated in the order.
API 5L line pipe transports oil, gas or water. API 5CT casing and tubing form part of the well construction. They serve different functions and require engineering approval before any substitution.
No. The minimum CVN energy depends on the grade band, outside diameter, test temperature, specification level and purchase requirements. The applicable table and test conditions must be stated in the order.
They are different product standards with different dimensional, threading, marking and verification requirements. API 5L line pipe should not be represented as API 5CT casing without a project specification and engineering approval.
This page shows J55, K55, N80, L80 and P110 as common reference grades. Availability, grade suffix, heat-treatment condition, connection and inspection are confirmed for each order.
Send the product standard, grade and suffix, outside diameter, wall thickness or weight, length, quantity, connection or end type, inspection requirements and destination. Casing and tubing quotations also need the well-service conditions and coupling or thread requirement.