Steel SM570
JIS SM570
SM570 is the highest-strength grade of the Japanese welded-structure rolled steel family, a micro-alloyed HSLA plate supplied as-rolled, normalized, TMCP or quenched and tempered, and broadly equivalent to Q460.
Reference datasheet — SM570 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 N condition
SM570 tempers and conditions
SM570 is supplied in 4 conditions, soft to hard. N is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
NDefault Normalized | Standard stocked condition: fine uniform grain, best combination of guaranteed yield and low-temperature toughness for bridge and heavy plate. | 490 | 630 | 24 | 190 HB | — |
As-rolled | Thin gauges (typically ≤16–25 mm) where micro-alloy precipitation alone meets 460 MPa yield; lowest cost. | 500 | 640 | 21 | 12 HRC | 8.6 % IACS |
Thermomechanically controlled processed | Choose for thick weldable plate: lower carbon equivalent means less or no preheat, with excellent toughness and flatness. | 500 | 625 | 25 | 195 HB | — |
Quenched and tempered | Used on heavy sections (>50 mm) to hold the 460 MPa yield class through thickness with tempered-bainite toughness. | 530 | 660 | 23 | 205 HB | — |
Supply forms, finishes and certifications
Ways SM570 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Z35 | Through-thickness (Z-direction) tested plate, ≥35 % RA short-transverse | Certification |
What is SM570?
SM570 is the highest-strength grade of the Japanese welded-structure rolled steel family, a micro-alloyed HSLA plate supplied as-rolled, normalized, TMCP or quenched and tempered, and broadly equivalent to Q460. It is chosen where 490 MPa yield, 630 MPa tensile, 24 % elongation and about 190 HB allow thinner sections in heavily welded plate structures; Z35 through-thickness qualities cover joints loaded in the short-transverse direction. It has no atmospheric corrosion resistance and only moderate formability, so it needs a full paint or galvanizing system, and hot forming must be followed by re-normalizing. Q460 plate is the usual substitute. SM570 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). SM570 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 630 MPa (91.4 ksi) — stronger than 61% of steel grades. Elongation at break is 24% and the elastic modulus is 206 GPa (29.9 Msi).
What is SM570 used for?
- bridge girders
- high-rise building frames
- penstocks
Advantages
- Tough — resists crack growth — 125 MPa·√m (113.8 ksi·√in), better than 85% of steel grades
- Readily welded — 72/100, better than 75% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
SM570 properties
Typical room-temperature values for SM570-N; bars are the position among steel grades.
Physical3
SM570 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
SM570 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 630 MPa (91.4 ksi) — stronger than 61% of steel grades. Elongation at break is 24% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
SM570 is rated for continuous service to 350°C (662 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
SM570 conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of SM570 takes about 27 MJ of energy and emits 2.2 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 25%.
Manufacturability7
SM570's machinability is fair (52/100, better than 52% of steel grades); weldability very good (72/100); formability good (55/100).
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. SM570 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SM570
Is SM570 easy to machine?
Machines like a tough 500 MPa-class HSLA plate — use rigid setups, coated carbide at ~120–180 m/min, and expect ~55 % of AISI 1212 tool life.
Can SM570 be welded?
Good weldability by SMAW/FCAW/SAW with 550–620 MPa-class low-hydrogen consumables; preheat 75–150 °C on thick or restrained joints and control interpass to protect the HAZ.
Can SM570 be formed, bent or molded?
Cold bend with inside radius ≥3t across the rolling direction; hot forming should be followed by re-normalizing to restore the guaranteed yield.
SM570 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 3106 ladle analysis | ≤ 0.18 | 0.16 |
| Si | ≤ 0.55 | 0.35 |
| Mn | ≤ 1.7 | 1.45 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.01 |
| Nboptional micro-alloy addition (Nb+V+Ti total typically ≤0.15 %) | ≤ 0.05 | 0.03 |
| Voptional micro-alloy addition | ≤ 0.1 | 0.04 |
| Tioptional, grain refinement | ≤ 0.03 | 0.02 |
| Fe | balance |
What surface finishes work on SM570?
No natural corrosion resistance — shot blast to Sa 2½ then apply zinc-rich epoxy paint systems, metallizing or hot-dip galvanizing (watch silicon level for zinc reactivity).
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 SM570 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- Q460
How much does SM570 cost?
SM570 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.
SM570 — frequently asked
What is SM570 used for?
SM570 is typically used for bridge girders, high-rise building frames and penstocks. In short: highest-strength JIS structural plate; weldable 570 MPa-class plate; Z35 through-thickness grade available.
What is the yield strength of SM570?
SM570 has a typical yield strength of 490 MPa (71.1 ksi) and a tensile strength of 630 MPa (91.4 ksi) — stronger than 61% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is SM570 easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines like a tough 500 MPa-class HSLA plate — use rigid setups, coated carbide at ~120–180 m/min, and expect ~55 % of AISI 1212 tool life.
Can SM570 be welded?
Yes — weldability is rated very good (72/100). Good weldability by SMAW/FCAW/SAW with 550–620 MPa-class low-hydrogen consumables; preheat 75–150 °C on thick or restrained joints and control interpass to protect the HAZ.
What surface finishes work on SM570?
No natural corrosion resistance — shot blast to Sa 2½ then apply zinc-rich epoxy paint systems, metallizing or hot-dip galvanizing (watch silicon level for zinc reactivity).
Can SM570 be formed, bent or molded?
Cold bend with inside radius ≥3t across the rolling direction; hot forming should be followed by re-normalizing to restore the guaranteed yield.
What is the maximum service temperature of SM570?
SM570 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 SM570-N and SM570-QT?
N is the default condition — standard stocked condition: fine uniform grain, best combination of guaranteed yield and low-temperature toughness for bridge and heavy plate. QT: used on heavy sections (>50 mm) to hold the 460 MPa yield class through thickness with tempered-bainite toughness. Yield strength is 490 MPa in N versus 530 MPa in QT.
How much does SM570 cost?
SM570 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 3106 Rolled steels for welded structure — Japanese Standards Association (2020)
- GB/T 1591 High strength low alloy structural steels (Q460) — SAC (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- Heavy plate for welded structures (SM570 / TMCP grades) — JFE Steel / Nippon Steel (2022)
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.