30MN
3 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 30MN →30Mn · GB/T 699-2015
Chemical composition source verified; this does not verify every standard clause, actual supply or measured heat results
- Material category
- Carbon steel
- Subcategory
- Quality carbon structural steel
- Material form
- Reference record
- Original record status
- Original standard verified
- Standard edition
- GB/T 699-2015
- Table / clause
- Table 1 and notes a and b; clauses 6.1.2 and 6.1.3
Carbon-equivalent reference
Composition
| Element | Composition requirement |
|---|---|
| C | 0.27 ～ 0.34 |
| Si | 0.17 ～ 0.37 |
| Mn | 0.7 ～ 1.0 |
| P | ≤ 0.035 (lower limit not stated) |
| S | ≤ 0.035 (lower limit not stated) |
| Cr | ≤ 0.25 (lower limit not stated) |
| Ni | ≤ 0.3 (lower limit not stated) |
| Cu | ≤ 0.25 (lower limit not stated) |
Applicability and limitations
Table 1 of GB/T699-2015 gives heat-analysis mass fractions wt%; Product-analysis tolerances are listed separately under GB/T222. ; Table 1, note a: Cu≤0.20% for steel intended for hot pressure working; other tabulated cases are ≤0.25%. ; 6.1.2: N≤0.008% applies to basic oxygen steelmaking; analysis may be omitted if the supplier guarantees compliance; Applicability depends on the steelmaking method. ; 6.1.3: for lead-bath-patented wire, Mn0.30–0.60% for 35–85 and Mn0.70–1.00% for 65Mn/70Mn, Cr≤0.10/Ni≤0.15/Cu≤0.20%; P/S follows the corresponding wire standard and must not exceed Table 1. This is a conditional exception, not a general range. ; Elements not specified in the table must not be intentionally added without purchaser consent.
Verification notes
Table 1 and applicable clauses verified30Mn · GB/T 699-1999
Chemical composition source verified; this does not verify every standard clause, actual supply or measured heat results
- Material category
- Carbon steel
- Material form
- Quality carbon structural steel (source classification)
- Original record status
- Original standard verified
- Standard edition
- GB/T 699-1999
- Table / clause
- Main-text Table 1, row 24, Table 2 and Clause 6.1.1
- PDF page references
- 5、6
- Unit
- Mass fraction (%)
- Analysis type
- Ladle analysis
Carbon-equivalent reference
Composition
| Element | Composition requirement |
|---|---|
| C | 0.27 ～ 0.34 |
| Si | 0.17 ～ 0.37 |
| Mn | 0.7 ～ 1.0 |
| Cr | ≤ 0.25 (lower limit not stated) |
| Ni | ≤ 0.3 (lower limit not stated) |
| Cu | ≤ 0.25 (lower limit not stated) |
| P | ≤ 0.035 (lower limit not stated) |
| S | ≤ 0.035 (lower limit not stated) |
Applicability and limitations
Edition 1999, main-text Table 1, row 24, unified numerical designation U21302. This record uses the default quality-steel class; heat analysis, mass fraction %. Table 2: for quality steel, P and S are each ≤0.035%; for higher-quality class A, each is ≤0.030%; for special-quality class E, the requirements are P≤0.025% and S≤0.020%. Do not apply A/E limits to the default class. 6.1.1.2—3: scrap-based steelmaking may permit Cu≤0.30%; steel for hot pressure working requires Cu≤0.20%. This record retains the default Cu≤0.25% in Table 1; specific conditions require separate confirmation. 6.1.1.4: Mn/Cr/Ni/Cu for lead-patented steel wire 35—85 has a separate restriction and does not apply to this default structural-steel record. Mechanical properties in Table 3 and 6.4 depend on specimens, dimensions, heat treatment and order requirements. Existing reference properties are not upgraded to universal guarantees by this composition review.
Verification notes
1999 original Tables 1/2 and clause 6.1.1 checked line by line.30Mn · GB/T 3078-2019
Chemical composition source verified; this does not verify every standard clause, actual supply or measured heat results
- Material category
- Carbon steel
- Subcategory
- Quality carbon structural steel
- Material form
- Cold-drawn bars
- Original record status
- Original standard verified
- Standard edition
- GB/T 3078-2019
Carbon-equivalent reference
Composition
| Element | Composition requirement |
|---|---|
| C | 0.27 ～ 0.34 |
| Si | 0.17 ～ 0.37 |
| Mn | 0.7 ～ 1.0 |
| P | ≤ 0.035 (lower limit not stated) |
| S | ≤ 0.035 (lower limit not stated) |
| Cr | ≤ 0.25 (lower limit not stated) |
| Ni | ≤ 0.3 (lower limit not stated) |
| Cu | ≤ 0.25 (lower limit not stated) |
Applicability and limitations
Clause 7.1.1 of GB/T3078—2019: quality carbon structural steel follows GB/T699, and alloy structural steel follows GB/T3077; The referenced composition standard must also be shown. This grade is listed in Table 2, row 16; Hardness by delivery condition is listed under separate conditions in Table 2; Actual use and delivery condition require separate verification and are not automatically treated as satisfied. Cold-drawn steel bars
cold-drawn polished round steel; Product-analysis tolerances under GB/T222 require separate verification and are not added to the heat-analysis range. Table 1 of GB/T699-2015 gives heat-analysis mass fractions wt%; Product-analysis tolerances are listed separately under GB/T222. Table 1, note a: Cu≤0.20% for steel intended for hot pressure working; other tabulated cases are ≤0.25%. 6.1.2: N≤0.008% applies to basic oxygen steelmaking; analysis may be omitted if the supplier guarantees compliance; Applicability depends on the steelmaking method. 6.1.3: for lead-bath-patented wire, Mn0.30–0.60% for 35–85 and Mn0.70–1.00% for 65Mn/70Mn, Cr≤0.10/Ni≤0.15/Cu≤0.20%; P/S follows the corresponding wire standard and must not exceed Table 1. This is a conditional exception, not a general range. Elements not specified in the table must not be intentionally added without purchaser consent.
Verification notes
The grade row in GB/T3078—2019, Table 2 and the 7.1.1 reference clause have been checked; Composition comes from verified original GB/T 699-2015, not a separate GB/T3078 composition tableHardness in the delivery condition (conditions shown separately)
GB/T 3078-2019 · Table 2 hardness in delivery condition and Note a; 7.3/7.4 · PDF pages 6, 7 · HBW
Standard condition data, not actual measured results of supplied heats; Actual delivery condition, application, and contract must be confirmed.
- Clause 7.3.1: The specific delivery condition shall be stated in the contract; if it is not specified, delivery shall be in the cold-drawn condition.
- 7.4.1 Hardness for delivery in the normalized condition shall be agreed by both parties; the two general-use columns in Table 2 do not apply to the normalized condition.
- Values in parentheses are for reference and are not acceptance criteria.
- 7.4.2 Hot-pressure-working applications are subject to separate limits; do not automatically apply the general condition in Table 2.
- 7.4.2 For hot-pressure working, supplied in the cold-drawn condition: 50Mn2, 35CrMnSi, 42CrMo and 35CrMoV per Table 2; 38CrSi and 38CrMoAl ≤285 HBW; other grades ≤269 HBW. Confirm the actual use; the ordinary Table 2 condition cannot replace this condition.
- 7.4.3 No hardness test is performed when the nominal cross-sectional dimension (diameter, thickness or diagonal length) is below 5 mm. At the purchaser’s request, stated in the contract, tensile strength may be used instead of hardness; the specific requirements shall be agreed by both parties. This clause provides no automatic conversion relationship.
Cold-drawn or cold-drawn and bright-polished delivery; Table 2 conditions are for general use. For hot-pressure-working applications, check clause 7.4.2 separately.
HBW：≤ 241 (lower limit not stated) HBW
Delivery in the annealed, bright-annealed, high-temperature-tempered or tempered-after-normalizing condition; delivery as-normalized is excluded and shall be agreed by both parties under 7.4.1.
HBW：≤ 197 (lower limit not stated) HBW