Chinese Steel Pipe Grade Cross Reference

A Chinese steel pipe grade can replace the grade on a drawing only when the project permits the proposed standard and the material meets the approved technical requirements. A similar name or a matching minimum yield strength is not enough. Before comparing prices, ask who will accept the material at the jobsite and what specification that acceptance will follow.

The practical sequence is to confirm whether alternatives are allowed, use a cross-reference table to identify a candidate, and submit a comparison for approval before production. The tables later in this article help buyers interpret GB, ASTM or ASME, EN, JIS and API names. The checks below explain how to turn that lookup into a purchase decision.

Buying seamless steel pipes or welded steel pipes from China does not require choosing a Chinese standard. Ask first whether the manufacturer can supply and certify the exact specification on the order. A GB alternative is a separate option, not an automatic consequence of Chinese origin.

Check whether the project accepts a Chinese standard

Obtain the material specification, relevant drawing revision and inspection requirements from the buyer or engineering team. Identify the party authorized to approve deviations, which may be the owner, design engineer or another appointed authority. Site inspection personnel cannot necessarily change a contract, design code or regulatory requirement just because a material appears suitable.

An approval should identify the original requirement, proposed standard and edition, full grade, dimensions and delivery condition. It should also record accepted deviations, additional tests and the affected order lines. A short email saying “equivalent accepted” leaves the receiving inspector without a reliable acceptance basis.

Compare the material against the actual service

Once alternatives are allowed, establish what the pipe will do. A structural support, a low-temperature process line and a high-temperature boiler tube may have similar room-temperature strength requirements but very different failure risks. Share the design conditions with the engineer reviewing the substitution; a sourcing table cannot establish a safe operating temperature or pressure.

The two standards do not need to use identical wording or identical numerical limits for an alternative to be technically acceptable. The proposed material must meet the requirements accepted for the project. Check both minima and maxima: higher strength or more alloy is not automatically better if it affects hardness limits, welding, fabrication or the design basis.

Separate a grade comparison from evidence for the supplied heat

Compare the specifications first, then the actual material. A sample mill test certificate helps evaluate the proposed manufacturing route, but it is not the certificate for the delivered pipes. The final material test certificate must identify the supplied heat and ordered tests, with traceability maintained through marking and packing.

A heat analysis that happens to fit another grade does not establish compliance with its entire product standard. Missing heat treatment records, an unperformed impact test or an unapproved manufacturing route cannot be corrected by changing the grade name on an invoice. Dual certification is useful only when the product genuinely satisfies both specifications and that compliance is properly documented.

How three common substitution requests should be handled

For an A106 Grade B order with a GB/T 8163 Grade 20 offer, first ask for direct A106 Grade B supply. If the buyer wants the GB option, ask whether the project permits it and compare the product requirements for the actual size and service. Grade 20 and boiler grade 20G are different specification contexts; neither name alone answers whether the offered pipe is acceptable.

For an S355J2H hollow-section order with a Q355D offer, the comparison must include the finished hollow-section standard and manufacturing condition, not just the base steel strength and toughness suffix. The engineer should review the actual thickness, section tolerances, impact requirements and certification before the buyer treats the price as a compliant alternative.

For an A335 P22 high-temperature pipe order with a 12Cr2MoG offer, a chromium-molybdenum family match only identifies a candidate. The reviewer still needs the applicable design-code material basis, service temperature, heat treatment and welding requirements. If that approval route is unavailable, purchase the specified P22 product instead of relying on a table label.

Use the tables to identify a candidate

The following tables retain the product context beside the grade. Carbon and alloy entries are approximate comparisons from manufacturer literature; stainless entries identify related designation families; line-pipe entries pair base grade names. Use the foreign designation to find the Chinese candidate, then return to the acceptance checks above. Historical catalogues are lookup aids, not replacements for the contractual standard editions.

Find the material family first

Rows marked comparison identify a sourcing or engineering-review candidate. Stainless rows identify related designation families. Line-pipe rows pair grade names. None of these relationships is a certificate of compliance. A dash means no counterpart is assigned in this table, not that the grade is unavailable.

Carbon steel pressure and boiler pipes

Keep the product standard beside the Chinese grade. Grade 20 under GB/T 8163 is a fluid-service pipe designation; 20G under GB/T 5310 is a high-pressure boiler designation. Their names are not interchangeable. The following common comparisons are useful for identifying which specifications to compare.

The boiler rows follow Baosteel’s published corresponding-grade table and are approximate comparisons. JIS STB designations belong to boiler and heat-exchanger tubes under G3461; STPT designations belong to high-temperature pressure pipes under G3456. An ASTM A192 tube is not a universal substitute for A106 pipe. Verify dimensions, heat treatment, test requirements and the design code before approval.

Answers to common carbon pipe lookup questions

Source: Baosteel boiler tube and pipe grade comparisons.

Chinese structural grades and European comparison names

These rows compare structural steel material families. They do not certify finished hollow sections. Q235 and Q275 are associated with GB/T 700; Q355 is associated with GB/T 1591. For structural hollow sections, add the applicable finished-product standard and manufacturing condition. The EN names below are material comparisons from Baosteel’s structural-steel reference, not an instruction to add an H suffix and declare EN 10210 or EN 10219 compliance.

B, C and D suffixes should not disappear from a quotation. The suffixes, thickness range and delivery condition affect the comparison. ASTM A36 is sometimes proposed alongside Q235, and A572 Grade 50 alongside Q355, but neither establishes the required hollow-section specification. For ASTM structural tubing, retain the applicable A500 or A1085 requirement instead of substituting a plate-grade label.

Source: Baosteel Q BQB 303 structural steel comparison appendix.

Alloy steel boiler tubes and pressure pipes

The ASTM tube column uses A213 unless a different standard is stated; the pipe column uses A335. Corresponding ASME specifications use SA prefixes. JIS boiler-tube grades use STBA under G3462 and alloy-pipe grades use STPA under G3458. EN candidates refer to the pressure-product family under EN 10216-2; verify that the selected product and edition actually include the grade.

The G-suffixed and modified boiler grades are encountered in GB/T 5310. The 5Cr and 9Cr I or NT grades are encountered in petrochemical pipe specifications; I and NT identify different delivery-condition variants and must be preserved. KA grades are Japanese power-generation approval designations, not ordinary JIS grade names without the prefix. P91 Type 1 and Type 2 also require explicit review rather than a generic P91 label.

For older records, 10Cr9Mo1VNb and other historical P91-related names may appear. Read the grade in its actual standard edition instead of silently adding or deleting N. Likewise, 12Cr1MoVG should not be relabelled P11 simply because both are chromium-molybdenum steels. If P11 is required, ask for A335 P11 or a separately approved alternative.

A current Chinese standard change to check

GB/T 9948-2025 took effect on 1 January 2026. The official standards catalogue records it as replacing GB/T 9948-2013, GB/T 6479-2013, GB/T 24592-2009 and GB/T 33167-2016. Its scope covers seamless steel tubes for petrochemical and chemical equipment. When a new RFQ still cites GB/T 6479-2013, resolve the contractual edition and replacement scope before quotation; do not change an approved legacy drawing without authorization.

Source: Chinese national standards catalogue for GB T 9948 2025.

Source: JFE seamless steel tube and pipe catalogue with ASTM EN and JIS comparisons.

Austenitic stainless steel Chinese grade lookup

The chemical-style Chinese name is the main lookup key. The separate GB numeric designation is not a UNS number, even when the characters look similar. For example, Chinese 06Cr19Ni10 has GB numeric ID S30408, while the familiar US Type 304 uses UNS S30400. These identifiers belong to different systems.

Where a row lists several EN numbers, compare their individual chemical limits instead of treating them as identical. The Chinese designation catalogue GB/T 20878-2024 is a grade-and-composition reference; a pipe order still needs its product standard. Common routes include GB/T 14976 for seamless stainless fluid pipe, GB/T 12771 for welded stainless fluid pipe, ASTM A312 for austenitic pipe, and EN 10216-5 or EN 10217-7 for the relevant pressure product. Confirm grade inclusion in the selected edition.

Older Chinese stainless names found on drawings

These are legacy-name lookup aids, not permission to rewrite an old certificate. Verify the drawing edition, composition and applicable product standard when an old and new name appear in the same order.

Source: Baosteel stainless grade and legacy designation catalogue.

Source: worldstainless international stainless designation comparison.

Duplex stainless pipe grades

S31803 and S32205 are both sold within the 2205 family but have different specified composition limits. A certificate stating only S31803 does not prove S32205 compliance. Chinese seamless duplex pipe is commonly specified under GB/T 21833, while ASTM A790 covers seamless and welded ferritic/austenitic pipe and A789 covers tubes. Require the actual specified grade, solution treatment and ordered corrosion or phase-control tests; a family name cannot establish service suitability.

Stainless grades for high temperature boiler tubes

The following GB/T 5310-related boiler designations help resolve H-grade and modified-alloy enquiries. They must not be substituted with ordinary fluid-pipe grades solely because their names begin with 304, 310, 321 or 347.

Source: T ZZB 0311 boiler tube designation comparison appendix.

Chinese line pipe names and API grade names

The strength value identifies the base grade name, not every permitted test result or design stress. Specify PSL, manufacturing route and required delivery-condition suffix. L360N and L360M, for example, must not be shortened to an unspecified L360 if the order depends on their delivery conditions. A Q355 structural certificate is not an API 5L X52 or GB/T 9711 L360 pipe certificate.

Edition control matters across these systems. API announced API 5L 47th edition in June 2026, while ISO 3183:2019 explicitly supplements the 46th edition. A slash-separated label such as API 5L / ISO 3183 / GB/T 9711 does not demonstrate that all contractual requirements are identical.

Ask for a quotation that can survive the acceptance review

Send us the original standard and grade, size and wall thickness, service conditions available for disclosure, delivery condition, tests, certification and the project rule on alternatives. Request the exact specified material as the base offer. If alternatives are allowed, ask for a separate GB offer with its deviations, additional testing cost and approval-dependent lead time clearly stated.

Compare the total consequence of the alternative: material price, engineering review, extra tests, fabrication changes and the risk of delaying approval. A lower mill price has little value if the pipes arrive before the project has accepted their specification. Do not authorize an alternative for production while its technical approval remains unresolved.

Frequently Asked Questions

Can jobsite approval alone make two grades interchangeable

The approval must come from the party authorized under the contract and applicable design or regulatory requirements. It must cover the proposed product and any deviations.

Must the chemistry and mechanical values be exactly identical

No. The proposed material must meet the approved requirements, including relevant limits and service conditions. Similarity by itself is insufficient, and higher values are not always acceptable.

What if the mill can supply the requested ASTM grade directly

Keep that as the base quotation. Chinese origin does not require a change to a GB standard.

What should accompany a substitution request

The original specification, proposed complete designation, comparison of requirements, supporting material evidence, deviations and a written decision from the responsible authority.

Related Reading

• Carbon Steel Pipe Standards and Grades Before Requesting a Quote
• ASTM A53 vs EN 10217-1 vs API 5L for ERW Pipe
• How to Read a Steel Pipe MTC

References and Sources

• GB T 20878 2024 official grade and composition standard record
• IMOA duplex stainless fabrication guide and designation table
• Baosteel stainless long products grade catalogue
• API announcement of API 5L 47th edition
• ISO 3183 2019 edition scope