10B21M

2 source records. Standards, editions and conditions are presented separately; matching grade names do not establish interchangeability.

Refer to each source for mass fractions and analysis type. Missing values are not treated as 0. Manufacturer typical values, standard guarantees and measured heat results must remain separate. Use the material selector for calculations and condition selection.

Open condition selection, comparison and carbon-equivalent tools for 10B21M →

10B21M · Q/BQB 517-2023

Chemical composition source verified; this does not verify every standard clause, actual supply or measured heat results

Material category: Alloy steel
Subcategory: Cold-heading steel
Material form: Hot-rolled steel wire rod for cold heading
Original record status: Original standard verified
Standard edition: Q/BQB 517—2023
Table / clause: 6.1.1/Table 1, row 54, note a
PDF page references: 10
Unit: Mass fraction (wt%)
Analysis type: Heat analysis

Source document

Carbon-equivalent reference

IIW / CEV：0.4067–0.5120Known-element contribution; incomplete value; missing V CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15; an engineering estimate of welding cold-cracking susceptibility for carbon and low-alloy steels.

Pcm（Ito–Bessyo）：0.2742–0.3423Known-element contribution; incomplete value; missing V Pcm = C + Si/30 + (Mn + Cu + Cr)/20 + Ni/60 + Mo/15 + V/10 + 5B; mainly used for low-carbon low-alloy steels, particularly modern low-carbon pipeline steels; more relevant when C is approximately no higher than 0.11%.

CET：0.3100–0.3760 Independent-element envelope of standard ranges; not measured heat-analysis values CET = C + (Mn + Mo)/10 + (Cr + Cu)/20 + Ni/40; used in welding preheat assessment for ferritic steels, subject to the applicability conditions of EN 1011-2.

Composition

Element	Composition requirement
C	0.2 ～ 0.23
Si	0.2 ～ 0.3
Mn	1.0 ～ 1.1
P	≤ 0.02 (lower limit not stated)
S	≤ 0.02 (lower limit not stated)
Cr	0.2 ～ 0.3
B	0.0015 ～ 0.003
Ni	≤ 0.2 (lower limit not stated)
Cu	≤ 0.2 (lower limit not stated)
Mo	≤ 0.06 (lower limit not stated)

Applicability and limitations

Q/BQB 517—2023, official original on the Baosteel website, Table 1, row 54; cast-analysis mass fraction wt%. Table footnote a: residual Cr≤0.20, Ni≤0.20, Cu≤0.20, Mo≤0.06 wt%; where this row specifies otherwise, its requirement for that element takes precedence. Unlisted elements and special agreement requirements must not be treated as zero or assumed guarantees; permitted product-analysis deviations are governed separately by GB/T 222. Wire rod is delivered hot rolled; stricter P/S under Z1 and special surface or inclusion quality must be confirmed under normative Annex A and the contractual ordering codes. Fixed mechanical properties must not be inferred from the chemistry table.

Verification notes

All 104 rows of Table 1 and 34 rows of Table 2 in the original Q/BQB517:2023 from Baosteel’s official website were checked row by row; not mixed with older editions.View associated products →

10B21M · BEXG 021-2020

Chemical composition source verified; this does not verify every standard clause, actual supply or measured heat results

Material category: Cold-heading steel
Subcategory: Cold-heading steel
Material form: Wire rod
Original record status: Manufacturer source verified
Document edition: BEXG 021-2020, sixteenth revision stated on the cover; issued and effective on 2020-12-29; The latest original document available on this computer only
Document title: Technical delivery conditions for cold-heading steel wire rod for automotive parts
Table / clause: Table 1
PDF page references: 4
Unit: Mass fraction (wt%)
Manufacturer: Baoshan Iron & Steel Co., Ltd. (Baosteel)

Carbon-equivalent reference

Estimate from manufacturer-published ranges, not a standard guarantee or measured heat result; formula applicability requires review against the application and process.

CET：0.3100–0.3760 Envelope of independent element limits from manufacturer data; neither standard guarantee values nor measured heat results CET = C + (Mn + Mo)/10 + (Cr + Cu)/20 + Ni/40; used in welding preheat assessment for ferritic steels, subject to the applicability conditions of EN 1011-2.

Composition

Element	Composition requirement
C	0.2 ～ 0.23
Si	0.2 ～ 0.3
Mn	1.0 ～ 1.1
P	≤ 0.02 (lower limit not stated)
S	≤ 0.02 (lower limit not stated)
Cr	0.2 ～ 0.3
B	0.0015 ～ 0.003
Ni	≤ 0.2 (lower limit not stated)
Cu	≤ 0.2 (lower limit not stated)
Mo	≤ 0.06 (lower limit not stated)

Applicability and limitations

Baosteel BEXG 021-2020, Table 1, row 9, PDF page 4; heat-analysis composition in wt%, hot-rolled wire rod. 2020 is the original edition available locally, with no claim that it is the company’s current latest edition. Special conditions and actual supply require separate confirmation.

Composition conditions

Table 1 and its continuation give heat composition, in mass fractions wt%; The product is hot-rolled wire rod for automotive parts.
Unless expressly stated otherwise, residual Cr≤0.20%, Ni≤0.20%, Cu≤0.20% and Mo≤0.06% apply; Specific requirements in the table and additional notes take precedence.
A dash does not mean zero; Composition outside the table is not inferred from grade names or referenced standards.

Verification notes

Table 1 original images checked page by page, physical pages 3–10; continuation values and other columns kept separate; two disputed rows excluded.

Source footnotes

B：0.0015-0.0030，Ni≤0.20，Cu≤0.20View associated products →