Steel SS400 · supply condition
Steel SS400-CR
Properties of the CR condition, compared with the other SS400 tempers.
Pick when a bright scale-free surface, tight thickness/diameter tolerance and higher yield are needed; ductility and bendability are reduced.
What is SS400-CR?
SS400-CR is SS400 supplied in the CR condition — pick when a bright scale-free surface, tight thickness/diameter tolerance and higher yield are needed; ductility and bendability are reduced. SS400-CR has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 67% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi). SS400-CR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; CR is available on request or by drawing note.
Advantages
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Easy to machine — 65/100, better than 93% of steel grades
- Conducts heat well — 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades
- Readily welded — 90/100, better than 90% of steel grades
- Forms and bends easily — 62/100, better than 78% of steel grades
SS400-CR properties
Typical room-temperature values for SS400-CR — 13 properties are specific to this condition; the rest are grade-level values shared by every SS400 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
SS400-CR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
SS400-CR has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 67% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SS400-CR is rated for continuous service to 350°C (662 °F). It conducts heat at 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
SS400-CR conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of SS400-CR takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability8
SS400-CR's machinability is good (65/100, better than 93% of steel grades); weldability excellent (90/100); formability good (62/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other SS400 tempers and conditions
SS400 is also supplied in 4 other conditions. The full side-by-side table is on the SS400 overview.
- HRDefaultDefault stock condition for plate, bar, angle and structural sections; cheapest, mill-scale surface, dimensional tolerances loose.280 MPa yield · 125 HB
- CRPick when a bright scale-free surface, tight thickness/diameter tolerance and higher yield are needed; ductility and bendability are reduced.380 MPa yield · 150 HB
- GalvanizedChoose for outdoor or damp-service parts that will not be painted; the zinc layer gives sacrificial protection but complicates welding and tight-radius forming.300 MPa yield · 130 HB
- NormalizedOccasionally ordered for thick plate or after heavy forming/flame cutting to refine grain and even out toughness; strength stays in the SS400 band.270 MPa yield · 120 HB
Working with SS400-CR
Is SS400 easy to machine?
Cuts easily but gummy: use sharp positive-rake tooling, 100–200 m/min carbide, generous coolant and chip breakers to avoid built-up edge and stringy chips.
Can SS400 be welded?
Excellent weldability by SMAW/GMAW/FCAW/SAW with E7018 or ER70S-6; no preheat needed below roughly 25 mm section at room temperature — strip zinc back on galvanized stock and ventilate.
Can SS400 be formed, bent or molded?
Hot-rolled sheet bends readily to ~1.5×t inside radius (2–3×t for cold-rolled or galvanized); roll, press-brake and stamp cold, hot-form above 900 °C for heavy sections.
What surface finishes work on SS400?
Not anodizable — remove mill scale by shot blast or pickling, then paint, phosphate+oil, zinc plate, hot-dip galvanize or powder coat; bare steel rusts within days indoors if humid.
SS400 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 |
|---|---|---|
| Cnot specified by JIS G3101 for SS400; mills typically 0.10–0.25 % | ≈ 0.17 | 0.17 |
| Sinot specified; typically ≤0.35 % | ≈ 0.2 | 0.2 |
| Mnnot specified; typically 0.30–0.80 % | ≈ 0.55 | 0.55 |
| PJIS G3101 limit (0.050 max) | ≤ 0.05 | 0.02 |
| SJIS G3101 limit (0.050 max) | ≤ 0.05 | 0.02 |
| Fe | balance | — |
SS400-CR — frequently asked
What is SS400-CR used for?
SS400-CR is typically used for welded structures, bridges and building frames. In short: workhorse Japanese mild plate.
What is the yield strength of SS400-CR?
SS400-CR has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 67% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is SS400-CR easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% of steel grades). Cuts easily but gummy: use sharp positive-rake tooling, 100–200 m/min carbide, generous coolant and chip breakers to avoid built-up edge and stringy chips.
Can SS400-CR be welded?
Yes — weldability is rated excellent (90/100). Excellent weldability by SMAW/GMAW/FCAW/SAW with E7018 or ER70S-6; no preheat needed below roughly 25 mm section at room temperature — strip zinc back on galvanized stock and ventilate.
What surface finishes work on SS400-CR?
Not anodizable — remove mill scale by shot blast or pickling, then paint, phosphate+oil, zinc plate, hot-dip galvanize or powder coat; bare steel rusts within days indoors if humid.
Can SS400-CR be formed, bent or molded?
Hot-rolled sheet bends readily to ~1.5×t inside radius (2–3×t for cold-rolled or galvanized); roll, press-brake and stamp cold, hot-form above 900 °C for heavy sections.
What is the maximum service temperature of SS400-CR?
SS400-CR 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 SS400-HR and SS400-CR?
HR is the default condition — default stock condition for plate, bar, angle and structural sections; cheapest, mill-scale surface, dimensional tolerances loose. CR: pick when a bright scale-free surface, tight thickness/diameter tolerance and higher yield are needed; ductility and bendability are reduced. Yield strength is 280 MPa in HR versus 380 MPa in CR.
Can FabDigit make parts in SS400-CR?
Yes — SS400-CR is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- JIS G3101 — Rolled steels for general structure — Japanese Standards Association (2020)
- GB/T 700 — Carbon structural steels (Q235B comparison) — SAC (2006)
- ASTM A36/A36M — Carbon structural steel — ASTM (2019)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook, 31st ed. (machinability ratings) — Industrial Press (2020)
- worldsteel LCI data for hot-rolled coil and plate — World Steel Association (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.