Steel E360-QT30
Hardness band
EN E360
QT30 = q&T 28–34 HRC
Water/oil quenched and tempered around 550–600 °C for tough, high-strength shafts and gear blanks made from this high-carbon grade.
Values for the QT30 condition
Other E360 tempers and conditions
E360 is listed in 6 conditions; see the grade overview at E360.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Lowest hardness condition for heavy machining, cold forming or before hardening; strength is well below the EN 10025-2 minima. | 330 | 610 | 20 | 180 HB | — |
+ARDefault Hot rolled | Standard mill delivery condition for E360 bar, section and plate; pick it for general machined structural and wear parts. | 380 | 730 | 12 | 215 HB | — |
Normalized | Choose when a uniform fine pearlitic structure and more consistent machining/heat-treat response is needed in heavy sections. | 390 | 720 | 14 | 210 HB | — |
Cold drawn | Cold-drawn bar for close tolerance, bright surface and higher strength shafts/pins; ductility and bendability are strongly reduced. | 640 | 830 | 7 | 23 HRC | — |
QT30This page Q&T 28–34 HRC | Water/oil quenched and tempered around 550–600 °C for tough, high-strength shafts and gear blanks made from this high-carbon grade. | 700 | 950 | 13 | 31 HRC | — |
Q&T 42–48 HRC | Hardened and tempered near 250–350 °C for wear surfaces, rails, cams and liners where hardness matters more than toughness. | 1,150 | 1,450 | 6 | 45 HRC | — |
What is E360-QT30?
E360-QT30 is E360 heat treated to QT30 — water/oil quenched and tempered around 550–600 °C for tough, high-strength shafts and gear blanks made from this high-carbon grade. E360-QT30 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 81% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi). E360-QT30 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). +AR is the default condition FabDigit quotes; QT30 is available on request or by drawing note.
Advantages
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
Limitations
- Limited formability — 12/100, worse than 92% of steel grades
- Difficult to machine — 32/100, worse than 87% of steel grades
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
- Limited ductility — 13%, worse than 78% of steel grades
E360-QT30 properties
Typical room-temperature values for E360-QT30; 13 are specific to this condition. Other listed values are E360 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
E360-QT30 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
E360-QT30 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 81% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
E360-QT30 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
E360-QT30 conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of E360-QT30 takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
E360-QT30's machinability is poor (32/100, worse than 87% of steel grades); weldability poor (20/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E360-QT30
Is E360 easy to machine?
Machine in the annealed or normalized state with carbide tooling, moderate speeds and generous coolant; expect abrasive pearlite wear and poor chip-breaking without free-machining additions.
Can E360 be welded?
Poor weldability — carbon equivalent above 0.5 demands 200–300 °C preheat, low-hydrogen consumables, controlled interpass and immediate stress relief to avoid HAZ martensite cracking.
Can E360 be formed, bent or molded?
Hot forge/roll at 1050–1200 °C with slow cooling; cold bending is limited to large radii and is best done after soft annealing.
What surface finishes work on E360?
No corrosion resistance of its own — protect with phosphate + oil, black oxide, zinc plating, hard chrome or paint; induction or flame hardening gives a wear-resistant case.
E360 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 limited by EN 10025-2 for E360; range is typical mill analysis needed to reach 670–830 MPa | 0.4 – 0.65 | 0.55 |
| Sitypical mill practice, not specified in EN 10025-2 | ≤ 0.4 | 0.25 |
| Mntypical mill practice, not specified in EN 10025-2 | 0.5 – 1.1 | 0.8 |
| PEN 10025-2 ladle analysis max | ≤ 0.05 | 0.02 |
| SEN 10025-2 ladle analysis max | ≤ 0.05 | 0.03 |
| NEN 10025-2 ladle analysis max (limit may be waived if N-binding elements present) | ≤ 0.01 | 0.01 |
| Fe | balance | — |
E360-QT30 — frequently asked
What is E360-QT30 used for?
E360-QT30 is typically used for high-strength shafts, wear plates, springs (light duty), cutting and forming tools (basic) and high-load machine pins. In short: highest-carbon EN engineering steel; wear resistance without alloying; poorest weldability in family.
What is the yield strength of E360-QT30?
E360-QT30 has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is E360-QT30 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 87% of steel grades). Machine in the annealed or normalized state with carbide tooling, moderate speeds and generous coolant; expect abrasive pearlite wear and poor chip-breaking without free-machining additions.
Can E360-QT30 be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — carbon equivalent above 0.5 demands 200–300 °C preheat, low-hydrogen consumables, controlled interpass and immediate stress relief to avoid HAZ martensite cracking.
What surface finishes work on E360-QT30?
No corrosion resistance of its own — protect with phosphate + oil, black oxide, zinc plating, hard chrome or paint; induction or flame hardening gives a wear-resistant case.
Can E360-QT30 be formed, bent or molded?
Hot forge/roll at 1050–1200 °C with slow cooling; cold bending is limited to large radii and is best done after soft annealing.
What is the maximum service temperature of E360-QT30?
E360-QT30 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 E360 +AR and E360-QT45?
+AR is the default condition — standard mill delivery condition for E360 bar, section and plate; pick it for general machined structural and wear parts. QT45: hardened and tempered near 250–350 °C for wear surfaces, rails, cams and liners where hardness matters more than toughness. Yield strength is 380 MPa in +AR versus 1,150 MPa in QT45.
Sources
- EN 10025-2 Hot rolled products of structural steels — Non-alloy structural steels — CEN (2019)
- DIN 17100 (superseded) — St 70-2 — DIN (1980)
- EN 10277 Bright steel products — technical delivery conditions — CEN (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)
- GB/T 699 (60 grade cross-reference) — SAC (2015)
- Mysteel / SMM (2025)
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.