Steel SCr430
JIS SCr430 · AISI/SAE 5130
SCr430 is a JIS chromium quenched-and-tempered steel (5130, 30Cr) for machine shafts and bolts that need moderate strength above plain carbon grades.
Reference datasheet — SCr430 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT condition
SCr430 tempers and conditions
SCr430 is supplied in 8 conditions, soft to hard. QT is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition — best for cold forming, deep machining or before final quench and temper. | 340 | 560 | 28 | 170 HB | — |
Hot rolled | Cheapest mill condition for parts that will be heat treated after rough machining. | 380 | 620 | 24 | 187 HB | 7.8 % IACS |
Normalized | Uniform fine-grain structure for forgings and weldments where full Q&T strength is not needed. | 450 | 700 | 22 | 210 HB | 7.8 % IACS |
Cold drawn | Close-tolerance bright bar with raised strength for shafts machined without further heat treatment. | 620 | 730 | 12 | 17 HRC | 7.7 % IACS |
QTDefault Quenched and tempered | Standard supply/service condition: 850–880 °C oil quench, 520–620 °C temper for balanced strength and toughness. | 720 | 880 | 18 | 27 HRC | — |
Induction hardened | Choose for shaft journals, splines and cam surfaces needing wear resistance over a tough Q&T core. | 730 | 900 | 15 | 52 HRC | 7.5 % IACS |
Q&T to 28–32 HRC | Specify when a defined hardness band is needed for shafts, keyed drives and machined fasteners. | 830 | 960 | 16 | 30 HRC | 7.8 % IACS |
Q&T to 32–36 HRC | Maximum practical through-hardened strength for SCr430 in small sections; toughness begins to drop. | 950 | 1,080 | 14 | 34 HRC | 7.8 % IACS |
What is SCr430?
SCr430 is a JIS chromium quenched-and-tempered steel (5130, 30Cr) for machine shafts and bolts that need moderate strength above plain carbon grades. In the default Q&T condition it provides about 720 MPa yield, 880 MPa tensile, 18 % elongation and 265 HB (27 HRC), and it also responds to induction hardening for local wear resistance. Service is limited to about 350 °C and there is no corrosion resistance, so plating or painting is required; welding needs preheat and post-weld temper because the carbon equivalent is around 0.6. SCr435 or SCM435 are the usual alternatives when higher strength or hardenability in thicker sections is required. SCr430 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). SCr430 has a yield strength of 720 MPa (104 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 82% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
What is SCr430 used for?
- shafts
- bolts
- machine structural parts
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- High strength — 720 MPa (104 ksi), better than 82% of steel grades
SCr430 properties
Typical room-temperature values for SCr430-QT; bars are the position among steel grades.
Physical3
SCr430 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
SCr430 has a yield strength of 720 MPa (104 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 82% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SCr430 is rated for continuous service to 350°C (662 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
SCr430 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of SCr430 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
SCr430's machinability is fair (52/100, better than 52% of steel grades); weldability fair (45/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. SCr430 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SCr430
Is SCr430 easy to machine?
Machines like 4130-class steel — best turned/milled in annealed or ≤300 HB Q&T state with carbide tooling and rigid setups; rough machine then heat treat, finish after temper.
Can SCr430 be welded?
Weldable with low-hydrogen filler but carbon equivalent ~0.6 demands 200–300 °C preheat, controlled interpass and post-weld temper/stress relief to avoid HAZ cracking.
Can SCr430 be formed, bent or molded?
Cold form only in the annealed condition with generous bend radii; hot forge 1150–850 °C followed by normalizing or full anneal.
SCr430 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CJIS G 4053 | 0.28 – 0.33 | 0.3 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cr | 0.9 – 1.2 | 1.05 |
| Niresidual max | ≤ 0.25 | |
| Curesidual max | ≤ 0.3 | |
| Fe | balance |
What surface finishes work on SCr430?
No inherent corrosion resistance — protect with zinc/Zn-Ni plating, phosphate + oil, black oxide, hard chrome or paint; bake plated Q&T parts to relieve hydrogen.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel SCr430 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- AISI / SAE
- 5130
- Similar grades
- 30Cr
How much does SCr430 cost?
SCr430 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
SCr430 — frequently asked
What is SCr430 used for?
SCr430 is typically used for shafts, bolts and machine structural parts. In short: mid-strength chrome shaft steel; 4130-class machinability; induction-hardenable surfaces.
What is the yield strength of SCr430?
SCr430 has a typical yield strength of 720 MPa (104 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 82% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is SCr430 easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines like 4130-class steel — best turned/milled in annealed or ≤300 HB Q&T state with carbide tooling and rigid setups; rough machine then heat treat, finish after temper.
Can SCr430 be welded?
With care — weldability is rated fair (45/100). Weldable with low-hydrogen filler but carbon equivalent ~0.6 demands 200–300 °C preheat, controlled interpass and post-weld temper/stress relief to avoid HAZ cracking.
What surface finishes work on SCr430?
No inherent corrosion resistance — protect with zinc/Zn-Ni plating, phosphate + oil, black oxide, hard chrome or paint; bake plated Q&T parts to relieve hydrogen.
Can SCr430 be formed, bent or molded?
Cold form only in the annealed condition with generous bend radii; hot forge 1150–850 °C followed by normalizing or full anneal.
What is the maximum service temperature of SCr430?
SCr430 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SCr430-QT and SCr430-A?
QT is the default condition — standard supply/service condition: 850–880 °C oil quench, 520–620 °C temper for balanced strength and toughness. A: softest condition — best for cold forming, deep machining or before final quench and temper. Yield strength is 720 MPa in QT versus 340 MPa in A.
How much does SCr430 cost?
SCr430 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- JIS G 4053 — Low-alloyed steels for machine structural use — JISC (2016)
- GB/T 3077 — Alloy structural steels (30Cr) — SAC (2015)
- SAE J404 / ASTM A29 — Chemical compositions of alloy steels (5130) — SAE / ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- Mysteel / SMM (30Cr) (2026)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.