Steel SM490 · supply condition · default condition
Steel SM490-HR
Properties of the HR condition, compared with the other SM490 tempers.
Default stock condition for structural plate, strip and sections; use for welded frames, bridges and machine bases.
What is SM490-HR?
SM490-HR is SM490 supplied in the HR condition — default stock condition for structural plate, strip and sections; use for welded frames, bridges and machine bases. SM490-HR has a yield strength of 365 MPa (52.9 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 71% of steel grades. Elongation at break is 23% and the elastic modulus is 206 GPa (29.9 Msi). SM490-HR 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).
Advantages
- Readily welded — 85/100, better than 83% of steel grades
- Tough — resists crack growth — 120 MPa·√m (109.2 ksi·√in), better than 80% of steel grades
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
SM490-HR properties
Typical room-temperature values for SM490-HR — 9 properties are specific to this condition; the rest are grade-level values shared by every SM490 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
SM490-HR 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
SM490-HR has a yield strength of 365 MPa (52.9 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 71% of steel grades. Elongation at break is 23% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
SM490-HR is rated for continuous service to 350°C (662 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
SM490-HR conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of SM490-HR takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
SM490-HR's machinability is good (55/100, better than 62% of steel grades); weldability excellent (85/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other SM490 tempers and conditions
SM490 is also supplied in 8 other conditions. The full side-by-side table is on the SM490 overview.
- HRDefaultDefault stock condition for structural plate, strip and sections; use for welded frames, bridges and machine bases.365 MPa yield · 160 HB
- CRChoose when tight thickness tolerance, clean surface and higher yield are wanted; ductility and bend radius suffer.480 MPa yield · 185 HB
Working with SM490-HR
Is SM490 easy to machine?
Machines like ordinary C-Mn structural steel (~55–60 % of 1212); use coated carbide, moderate speeds and generous coolant, expect gummy chips and mill-scale abrasion on the first pass.
Can SM490 be welded?
Designed for welding — SMAW/GMAW/SAW with E70xx-class consumables; preheat 50–150 °C for thick or restrained joints and keep hydrogen low to avoid HAZ cracking.
Can SM490 be formed, bent or molded?
Good hot forming and press braking; keep cold bend radius ≥2t (≥3t for thick plate) and bend transverse to the rolling direction.
What surface finishes work on SM490?
Blast off mill scale then zinc-rich primer, paint or hot-dip galvanize; not anodizable and bare surfaces rust quickly outdoors.
SM490 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 |
|---|---|---|
| C≤0.20 for t≤50 mm, ≤0.22 for t>50 mm (SM490A/YA/YB); ≤0.18 for SM490C | ≤ 0.2 | 0.16 |
| Si | ≤ 0.55 | 0.3 |
| MnSM490C: 1.60 max, deoxidized/killed practice | ≤ 1.6 | 1.3 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.01 |
| Febalance, plus residual Cu/Ni/Cr and micro-alloy additions at mill option | balance | — |
SM490-HR — frequently asked
What is SM490-HR used for?
SM490-HR is typically used for welded bridge girders, industrial building frames, crane and gantry structures, pressure-bearing structural frames, heavy machine bases and weldments and galvanized structural sections. In short: japanese structural plate.
What is the yield strength of SM490-HR?
SM490-HR has a typical yield strength of 365 MPa (52.9 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 71% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is SM490-HR easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines like ordinary C-Mn structural steel (~55–60 % of 1212); use coated carbide, moderate speeds and generous coolant, expect gummy chips and mill-scale abrasion on the first pass.
Can SM490-HR be welded?
Yes — weldability is rated excellent (85/100). Designed for welding — SMAW/GMAW/SAW with E70xx-class consumables; preheat 50–150 °C for thick or restrained joints and keep hydrogen low to avoid HAZ cracking.
What surface finishes work on SM490-HR?
Blast off mill scale then zinc-rich primer, paint or hot-dip galvanize; not anodizable and bare surfaces rust quickly outdoors.
Can SM490-HR be formed, bent or molded?
Good hot forming and press braking; keep cold bend radius ≥2t (≥3t for thick plate) and bend transverse to the rolling direction.
What is the maximum service temperature of SM490-HR?
SM490-HR 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 SM490-HR and SM490-CR?
HR is the default condition — default stock condition for structural plate, strip and sections; use for welded frames, bridges and machine bases. CR: choose when tight thickness tolerance, clean surface and higher yield are wanted; ductility and bend radius suffer. Yield strength is 365 MPa in HR versus 480 MPa in CR.
Can FabDigit make parts in SM490-HR?
Yes — SM490-HR 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 G 3106 Rolled steels for welded structure — JISC (2020)
- GB/T 1591 Q345B (equivalent low-alloy structural steel) — SAC (2018)
- ASM Handbook Vol.1 — Properties of Carbon and Low-Alloy Steels — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- Structural plate product guide (SM490A/B/C) — Nippon Steel / JFE Steel (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.