Printed from Kezuriba (kezuriba.net/en/materials/scm440/)
SCM440
ISO P (steel)Alloy steels for machine structural use (chromium-molybdenum steels). Standard: JIS G 4053.
🌐International equivalents
“Close” means composition or properties are not exactly the same. Before substituting, check the values in each standard.
| System | Designation | Number | Relation | Confidence |
|---|---|---|---|---|
| JIS | SCM440 | JIS G 4053 | — | |
| AISI/SAE | 4140 | UNS G41400 | close | Agrees in 2+ sources[9][10][2] |
| EN | 42CrMo4 | 1.7225 | close | Agrees in 2+ sources[9][10][11] |
| GB | 42CrMoGB/T 3077 alloy structural steels | close | One source / reference[9] |
Differences between the equivalents (from the sources)
- AISI/SAE 4140: Kyocera's metal material designation comparison table places SCM440 alongside AISI 4140 and 4142. DEW's 42CrMo4 datasheet lists SCM440 and SCM440H in its JIS column, 4137 and 4140 in its AISI column, and UNS G41400. The UNS number was also confirmed in the SAE standards table in Nippon Steel's "Bars and Wire Rods" catalog (4140 = G41400)
- EN 42CrMo4: Agrees between Kyocera's comparison table and DEW's datasheet (SCM440 in its JIS column). 42CrMo4 in EN 10083-3 has C 0.38–0.45, Si ≤0.40, Mn 0.60–0.90, P ≤0.025, S ≤0.035, Cr 0.90–1.20, Mo 0.15–0.30 (thyssenkrupp Materials Services), which differs from JIS in the upper limit of C (JIS 0.43), Si and P. DEW's table gives the upper limit of Mn as 0.99, which disagrees with thyssenkrupp (0.90) (possibly a misprint on DEW's side, but not confirmed)
- GB 42CrMo: From the GB column of Kyocera's comparison table only. GB-side composition could not be obtained from primary sources
📄Related specifications (AMS, ASTM etc.)
Specifications called up on purchase orders and drawings. AMS are SAE aerospace material specifications, split by product form (bar, plate, forging), melting practice and heat treatment. Standard texts are paid, so only titles and scopes checked on the publishers’ public pages are shown.
| Spec | Scope | Confidence |
|---|---|---|
| ASTM A331 | Standard Specification for Steel Bars, Alloy, Cold-Finished (Withdrawn 2004)Cold-finished alloy steel bars. Listed in the ASTM column of DEW's 42CrMo4 datasheet, but the ASTM page shows it was withdrawn in 2004 (successor: A108) | One source / reference[12][10] |
All ASTM standards on Kezuriba: ASTM standards quick reference.
⚗Chemical composition (mass %)
As specified in JIS G 4053
| Element | Range | Confidence |
|---|---|---|
| C | 0.38 – 0.43 | Agrees in 2+ sources[7][3][8] |
| Si | 0.15 – 0.35 | Agrees in 2+ sources[7][3][8] |
| Mn | 0.6 – 0.9 | Agrees in 2+ sources[7][3][8] |
| P | ≤ 0.03 | Agrees in 2+ sources[7][3][8] |
| S | ≤ 0.03 | Agrees in 2+ sources[7][3][8] |
| Cu | ≤ 0.3 | Agrees in 2+ sources[7][3] |
| Ni | ≤ 0.25 | Agrees in 2+ sources[7][3] |
| Cr | 0.9 – 1.2 | Agrees in 2+ sources[7][3][8] |
| Mo | 0.15 – 0.30 | Agrees in 2+ sources[7][3][8] |
⚖Density
—
Not confirmed
The density of SCM440 was not found in Japanese primary sources. For EN 42CrMo4, the thyssenkrupp Materials Services datasheet gives 7.85 and DEW gives 7.72 kg/dm³, which disagree, so neither is adopted (treated the same as scm435.json)
The density could not be confirmed. In the weight calculator, use “Steel, general value” or enter your own.
💪Mechanical properties
“Reference” values are not specified minimums from the standard but figures published by makers and others.
| Condition | Tensile MPa | Yield MPa | Elong. % | Hardness | Type of value |
|---|---|---|---|---|---|
| Quenched and tempered (quenching 830–880℃ oil cooled / tempering 530–630℃ rapid cooling) | ≥ 980 | ≥ 835 | ≥ 12 | HB 285-352 | Reference value (from the manufacturer's standards table, "(Reference) Example material data for alloy steels for machine structural use". Not a JIS specified value) Agrees in 2+ sources[3][8] |
| Annealed approx. 830℃, furnace cooled | — | — | — | HB 179-217 | Reference value (Sanyo Special Steel; the table marks it as a reference value) One source / reference[8] |
1 MPa ≈ 145 psi (0.145 ksi). Hardness conversion · unit converter
🔧Machinability notes (as stated in the sources)
📚Sources
Primary sources (public documents from makers, industry associations and standards bodies), numbered where each value is cited. Many are in Japanese.
- webdesk.jsa.or.jp https://webdesk.jsa.or.jp/preview/pre_jis_g_04053_000_000_2023_j_ed10_ch.pdf
- nipponsteel.com https://www.nipponsteel.com/product/catalog_download/__icsFiles/afieldfile/2026/04/23/B001…
- kobelco.co.jp https://www.kobelco.co.jp/products/steel-aluminum/wirerod/pdf/202012_wirerod_standard.pdf
- sandvik.coromant.com https://www.sandvik.coromant.com/en-us/knowledge/materials/workpiece-materials
- kyocera.co.jp https://www.kyocera.co.jp/prdct/tool/wp-content/uploads/2014/07/2024-2026_A.pdf
- sumitool.com https://www.sumitool.com/downloads/cutting-tools/general-catalog/assets/pdf/a.pdf
- nipponsteel.com https://www.nipponsteel.com/product/catalog_download/__icsFiles/afieldfile/2025/09/10/U006…
- sanyo-steel.co.jp https://www.sanyo-steel.co.jp/product/special_steel/images/pdf/akahon_201906.pdf
- kyocera.co.jp https://www.kyocera.co.jp/prdct/tool/wp-content/uploads/2016/06/R_2016.pdf
- swisssteel-group.com https://swisssteel-group.com/content-media/documents/Data-Sheets/Engineering-Steel/1.7225_…
- ucpcdn.thyssenkrupp.com https://ucpcdn.thyssenkrupp.com/_binary/UCPthyssenkruppBAMaterialsSchulte/dc4e3d67-9afe-4b…
- store.astm.org https://store.astm.org/a0331-95r00.html