How does GOST 9940 steel pipe differ from GOST 9941 and GOST 24030 standards?

For procurement and EPC teams sourcing Russian/CIS-compliant stainless steel tubes, three GOST numbers come up again and again: GOST 9940, GOST 9941 and GOST 24030. On paper they all describe "seamless corrosion-resistant steel tubes," yet each one targets a different manufacturing route, size range and end use. Picking the wrong standard can mean re-ordering tubes, repassing pressure tests, or rejecting an entire heat at incoming inspection.

This guide breaks down where the three standards overlap and where they don't, so you can match the spec to your service conditions the first time.

Quick overview of the three standards

All three standards reference the same steel-grade catalog (GOST 5632) and use the same corrosion-test methodology (GOST 6032). The differences live in how the tube is made, what size and tolerance it covers, and which service it is qualified for.

Manufacturing route: the most fundamental difference

GOST 9940 is the hot-worked standard. The starting billet is pierced and rolled (or extruded) above the recrystallization temperature, then sized and straightened. This route is preferred for heavy-wall and large-diameter tubes, and it produces the typical "as-hot-rolled" or pickled surface finish.

GOST 9941 is the cold-worked standard. A hot-finished tube is reduced further by cold drawing or cold rolling, which tightens dimensional tolerances, improves surface finish, and increases yield strength through work hardening. The 2022 revision (GOST 9941-2022) explicitly folded the old "warm-deformed" category into the cold-deformed scope, simplifying classification.

GOST 24030 is not defined by forming temperature alone. It is a by-application standard: tubes must be suitable for power-engineering service, which means specific combinations of steel grade, mechanical properties, dimensional control, and mandatory testing. Both cold-deformed and hot-deformed product can be supplied under GOST 24030 as long as the energy-machinery requirements are met.

In short: GOST 9940 and GOST 9941 describe how the tube is made; GOST 24030 describes where the tube is allowed to go.

Size range and dimensional tolerance

Because cold working only pays off on smaller cross-sections, GOST 9941 covers a much narrower OD band than GOST 9940.

• GOST 9940-81 – Mainstream OD: 76, 83, 89, 95, 102, 108, 114, 121, 127, 133, 140, 146, 152, 159, 168, 180, 194, 219, 245, 273, 325 mm. Wall thickness typically 3.5 to 28 mm. Diameter tolerance is given as a percentage (e.g., ±1.5% normal, ±1.0%/-1.25% improved) and wall tolerance follows the standard ±12.5%/-15% bands.
• GOST 9941-81 / 9941-2022 – OD generally 5 to 95 mm, with several precision tolerance classes. Because the tube is cold drawn, OD and wall tolerances are far tighter than GOST 9940, which is why 9941 is the default choice for instrument and heat-exchanger tubing where concentricity and surface finish matter.
• GOST 24030-80 – Size table covers both cold- and hot-deformed ranges. For cold-deformed tubes, the standard also allows random lengths of 1.5–8 m (up to 12.5 m by agreement, and up to 16 m for tubes up to 25 mm by agreement). For hot tubes, length is defined by table with random lengths of 1.5–7 m. These length rules are tighter than the more generic 9940/9941 wording and exist because power-plant piping has very specific layout constraints.

If your line pipe is over 100 mm OD or carries a thick wall, you are almost always in GOST 9940 or GOST 24030 territory. If you need precision tubing under 100 mm OD, you are in GOST 9941.

Steel grades and mechanical properties

All three standards draw from the GOST 5632 grade catalog, so you will see the same familiar designations such as 08Х18Н10Т (≈ AISI 321), 12Х18Н10Т, 08Х17Н13М2Т (≈ AISI 316Ti), 10Х17Н13М2Т, 08Х22Н6Т (duplex), 10Х23Н18 and 08Х20Н14С2. However, not every grade is permitted in every standard, and the strength numbers differ.

GOST 9940 specifies tensile strength and elongation per grade (for example, 08Х17Т at 392 MPa min, 08Х18Н10 at 510 MPa min, 12Х18Н10Т at 530 MPa min, 08Х22Н6Т at 589 MPa min). For heavy-wall austenitic tubes with a D/t ratio of 8 or less, an additional 20 MPa reduction in tensile is permitted.

GOST 9941 cold-drawn tubes show higher tensile values for the same grade because of the work-hardening effect, and the standard controls elongation, hardness and surface roughness more tightly.

GOST 24030 inherits the GOST 5632 grade table but layers additional requirements for high-temperature service: creep strength, long-term strength at operating temperature, and additional batch testing for tubes intended for boilers, superheaters and reheaters.

Testing and acceptance differences

Each standard carries its own testing matrix, which is where most procurement disputes begin.

GOST 9940-81 mandatory and optional tests

• Hydraulic test on every tube; permissible test stress is 40% of σ_B for the applicable steel grade.
• Flattening test on request for austenitic tubes with wall thickness under 10 mm.
• Expansion test (10% OD increase) on request for austenitic tubes under 10 mm wall.
• Intercrystalline corrosion (ICC) test on request for the listed austenitic and Ti-stabilized grades.
• Non-destructive testing only by agreement.

GOST 9941-81 / 9941-2022 testing scope

• Hydraulic test on every tube.
• Mechanical tests (tensile, elongation) and ICC testing in line with the steel grade.
• Dimensional and surface-quality inspection on 100% of tubes because of the tighter tolerance class.
• The 2022 revision adds clarified references to GOST ISO 10893-10 for NDT and tightens a number of supplementary requirements inherited from the 1981 version.

GOST 24030-80 testing scope

• Mandatory chemical analysis, tensile, elongation and hardness for each batch.
• Hydraulic test on every tube.
• ICC test for grades that will be exposed to high-temperature water and steam.
• Surface quality control, with grinding or local machining allowed for defect removal as long as wall and diameter remain within tolerance.
• Optional non-destructive testing, ultrasonic or eddy current, on agreement.

The practical takeaway: if you need ICC-tested tubes by default, you should write it into the order. None of the three standards makes every test mandatory on every tube.

Choosing the right standard for your project

Use the following rule of thumb when reviewing an inquiry or an RFQ:

• Large-bore, heavy-wall process piping for refineries, chemical plants or sea-water service → GOST 9940 stainless steel pipe as the default, with optional ICC and NDT upgrades.
• Small- to medium-bore tubing for instrumentation, sampling lines, condensers, sanitary systems and tight-tolerance service → GOST 9941 stainless steel tube in cold-drawn condition.
• Boilers, superheaters, reheaters, turbine auxiliaries, and any high-temperature steam circuit → GOST 24030 with the right grade (often 12Х18Н10Т, 08Х18Н10Т or higher-Cr grades) and full ICC testing.

For EPC packages that combine several service environments, you can also see GOST 9940 or GOST 9941 specified together with GOST 24030 in the same material take-off, each covering the section of the system that fits its scope.

Sourcing and supply considerations

Whichever standard you choose, a few points will make the order go smoothly:

1. State the standard by full designation, including the year (9940-81, 9941-81 or 9941-2022, 24030-80). The 2022 revision of 9941 is the current issue and should be referenced for new projects unless a contractual exception is in place.
2. List the steel grade by GOST 5632 designation and cross-reference to UNS/AISI if the design uses both.
3. Specify dimensional class (normal or improved tolerance) and surface condition (as-hot-rolled, pickled, polished, scale-free).
4. Confirm which tests are mandatory versus on-request, and put the answer in the purchase order to avoid ambiguity at inspection.
5. Require an MTC (mill test certificate) per GOST 10692, including chemical analysis, mechanical results, ICC results (if applicable) and NDT report (if applicable).

At EZ Steel Industrial, we supply GOST 9940, GOST 9941 and GOST 24030 seamless stainless tubes from our Cangzhou, Yangzhou and Lishui production bases, with raw-material traceability, in-house NDT (ultrasonic and hydrostatic), positive material identification and mill test certificates. Tubes can be delivered in standard sizes, cut-to-length, or finished as part of a bundled piping package together with fittings, flanges, gaskets, stud bolts and valves for project ｄｒｏｐ-shipment.

Send us your datasheet and we will recommend the right standard, grade and size combination for your service conditions, and quote you within one business day.