Near-identical grades: carbon (0.28–0.33%), chromium and molybdenum windows overlap, but JIS specifies higher manganese (0.60–0.85% vs 0.40–0.60%) and a Mo ceiling of 0.30% vs 0.25%. For Q&T bar work they are routinely cross-supplied against mill certificates.

Grades · Alloy & Engineering Steel · SCM430

SCM430

Data verified

SCM430 is the JIS G4053 chromium-molybdenum machine structural steel corresponding to AISI 4130, with a slightly higher manganese and chromium window in the JIS specification. It is one of the most traded alloy round bars in Japan and Southeast Asia for shafts, bolts and hydraulic components.

DIN25CrMo4 / 1.7218 (near)

AISI4130

JISSCM430 (JIS G4053)

CategoryAlloy & Engineering Steel

Chemical composition

Element	Content (%)
C	0.28–0.33
Si	0.15–0.35
Mn	0.60–0.85
P	≤0.030
S	≤0.030
Cr	0.90–1.20
Mo	0.15–0.30

Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.

Properties

Tensile strength	≥830 MPa (Q&T reference)
Yield strength	≥685 MPa (Q&T reference)
Density	7.85 g/cm³

Heat treatment

Quench 850–880 °C in oil; temper 550–650 °C to the required hardness. Normalize before machining for best consistency.

Equivalent grades

Standard	Designation
din	25CrMo4 / 1.7218 (near)
aisi	4130
jis	SCM430 (JIS G4053)
gb	30CrMo (near)

Compare side by side: SCM430 vs 4130 · SCM430 vs SCM435

Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.

Applications & Processing

Applications: Shafts, studs and high-tensile bolts, hydraulic cylinder parts, bicycle and motorcycle frames, general machine components.

Processing: Machines well in the annealed or normalized condition; weldable with preheat and controlled cooling, though most parts are used bolted or machined rather than welded.

FAQ

SCM430 vs AISI 4130?: Near-identical grades: carbon (0.28–0.33%), chromium and molybdenum windows overlap, but JIS specifies higher manganese (0.60–0.85% vs 0.40–0.60%) and a Mo ceiling of 0.30% vs 0.25%. For Q&T bar work they are routinely cross-supplied against mill certificates.

Need SCM430 from stock?

Steel.Wiki is sponsored by Shenzhen NewAsia Special Steel (Nasteel), a special-steel stockholder in Shenzhen stocking mold, tool and alloy steels with EN 10204 3.1 certification.

Ask for a quotation Visit Nasteel

Source: JIS G4053 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.