Chinese Valve Material Grades Decoded: 20#, WCB, 16Mn, 06Cr19Ni10 vs ASTM & EN

Why Chinese Material Grades Confuse International Buyers

A Chinese valve quotation rarely lists "ASTM A216 WCB". More often it reads "body: WCB", "body: 20#", "body: CF8", or "body: 06Cr19Ni10". For an engineer trained on ASTM or EN designations, these markings look like a private code. They are not. China has a long-established, standards-based material nomenclature (chiefly GB/T 12229 for cast carbon steel, GB/T 12228 / GB/T 699 for forged carbon steel, and GB/T 12230 / GB/T 20878 for stainless), and almost every Chinese grade maps cleanly onto ASTM, EN or JIS.

The confusion comes from three habits: (1) some grades share the ASTM name exactly (WCB, CF8), (2) some use a plain "20#" style that has no ASTM letter equivalent, and (3) the 2007 GB/T 20878 revision renamed the stainless grades, so both old and new markings circulate. This guide untangles all three.

The Core Principle: Cast and Forged Are Separate Chains

The single most useful rule: in China, as in ASTM, casting and forging grades are distinct even when the chemistry is similar. A valve body is usually a casting (WCB, CF8, LCB); the stem and some trim are forgings (A105, F304, LF2). When a quote says "WCB body, A105 stem", that is correct practice, not a mismatch. The pairs are stable:

• WCB (cast) pairs with A105 (forged)
• CF8 (cast) pairs with F304 (forged)
• CF8M (cast) pairs with F316 (forged)
• LCB / LCC (cast) pairs with LF2 (forged)

Carbon and Low-Alloy Grades

These are the workhorse bodies for water, steam, oil and gas. Temperatures are representative service limits from the Chinese material tables and align with ASTM B16.34 material groups.

Note the "20#" case: 20 steel (GB/T 699) is a plain-carbon grade whose chemistry sits between ASTM A105 and a mild plate grade. Chinese foundries quote it for forged carbon-steel bodies and stems; if the body is a casting, the Chinese marking is WCB (ZG230-450), not 20#.

Stainless and Corrosion-Resistant Grades

Austenitic stainless is where the 2007 rename causes the most trouble. Both columns below are the same material.

The martensitic grade 1Cr13 / 12Cr13 (and 2Cr13 / 20Cr13) is common as hard-faced trim, not as a corrosion-resistant body. It corresponds to ASTM 410 / 420 and is not a substitute for 304 in aggressive media.

The GB/T 20878 Renaming at a Glance

If you only memorise one table, memorise this:

• 0Cr18Ni9 = 06Cr19Ni10 = ASTM 304
• 00Cr19Ni10 = 022Cr19Ni10 = ASTM 304L
• 0Cr17Ni12Mo2 = 06Cr17Ni12Mo2 = ASTM 316
• 00Cr17Ni14Mo2 = 022Cr17Ni12Mo2 = ASTM 316L
• 1Cr18Ni9Ti (old) approx = ASTM 321 (stabilised with titanium)

Suppliers quoting the old "0Cr" style are not using inferior material; they are using pre-2007 notation. Pressure-temperature ratings are unchanged.

Low-Temperature Grades

Below -29 deg C, ordinary 20# / WCB is not acceptable. The Chinese low-temperature chain mirrors ASTM:

• -46 deg C service: 16Mn forged (A350 LF2), or LCB / LCC cast
• -101 deg C and below: 300-series austenitic stainless (06Cr19Ni10 / CF8), which keeps its impact toughness at cryogenic temperatures

Always confirm the design temperature against the quoted grade before accepting a substitution.

A Practical Decoding Rule

1. If the grade is a direct ASTM letter (WCB, CF8, CF8M, LCB), treat it as that ASTM grade.
2. If the grade is "20#" or "16Mn", map it to A105 or LF2 respectively and confirm whether the part is cast or forged.
3. If the grade starts with "0Cr" or "00Cr", convert using the GB/T 20878 table above before comparing to 304 / 316.
4. For trim, expect martensitic 1Cr13 / 2Cr13 (410 / 420) on hard-faced seats, not 304.
5. Cross-check the quoted body and trim materials against a verified specification database before procurement.

Our Chinese-to-international valve standards cross-reference covers the flange and pressure-class side of the same problem, and the valve body and trim material compatibility guide explains fluid-by-fluid material selection. Body and trim materials for more than ninety manufacturers are catalogued in the ValveSpecs Pro database, which makes it straightforward to confirm whether a quoted material genuinely meets an ASTM or EN requirement.