Steel E335 QT-34-38HRC
Hardness band
EN E335
QT-34-38HRC = +QT
Higher-strength condition for small-section gears, pins and couplings; limited to thin sections due to modest hardenability.
Values for the QT-34-38HRC condition
Other E335 tempers and conditions
E335 is listed in 8 conditions; see the grade overview at E335.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition, chosen when heavy machining, cold forming or subsequent hardening is planned. | 310 | 560 | 24 | 160 HB | — |
+ARDefault Hot rolled | Standard mill delivery condition for bar, plate and sections; meets EN 10025-2 E335 minimums as-rolled. | 355 | 620 | 18 | 180 HB | — |
Normalized | Choose for uniform fine-grain structure and better toughness/machining consistency in heavy sections before further machining. | 360 | 610 | 20 | 175 HB | 10 % IACS |
+QT | Tough, machinable condition for medium-loaded shafts and levers in thick sections where full hardening is impractical. | 470 | 700 | 18 | 18 HRC | 10 % IACS |
Cold drawn | Bright bar with tight tolerance and higher strength; pick for shafts and machined parts needing good surface without turning. | 560 | 700 | 10 | 210 HB | — |
Induction/flame hardened surface, 50–56 HRC case on Q&T core | Pick when wear-resistant journals, gear teeth or guide ways are needed on an otherwise tough medium-carbon part. | 650 | 900 | 13 | 53 HRC | 9 % IACS |
+QT | Common machine-part condition: good strength/toughness balance, still machinable with carbide tooling. | 680 | 900 | 15 | 30 HRC | — |
QT-34-38HRCThis page +QT | Higher-strength condition for small-section gears, pins and couplings; limited to thin sections due to modest hardenability. | 850 | 1,100 | 12 | 36 HRC | — |
What is E335 QT-34-38HRC?
E335 QT-34-38HRC is E335 heat treated to QT-34-38HRC — higher-strength condition for small-section gears, pins and couplings; limited to thin sections due to modest hardenability. E335 QT-34-38HRC has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 88% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi). E335 QT-34-38HRC 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; QT-34-38HRC is available on request or by drawing note.
Advantages
- High strength — 850 MPa (123 ksi), better than 88% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% 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 — 8/100, worse than 97% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
- Difficult to weld — 22/100, worse than 81% of steel grades
E335 QT-34-38HRC properties
Typical room-temperature values for E335 QT-34-38HRC; 12 are specific to this condition. Other listed values are E335 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
E335 QT-34-38HRC 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
E335 QT-34-38HRC has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 88% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
E335 QT-34-38HRC 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 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
E335 QT-34-38HRC 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 E335 QT-34-38HRC takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
E335 QT-34-38HRC's machinability is good (55/100, better than 62% of steel grades); weldability poor (22/100); formability not recommended (8/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E335 QT-34-38HRC
Is E335 easy to machine?
Machines well with carbide at ~120–180 m/min in the hot-rolled or annealed state; above 30 HRC drop speed and use rigid setups and coolant.
Can E335 be welded?
Weldable but crack-sensitive: CEV ≈ 0.55–0.65, so use low-hydrogen consumables, preheat 150–250 °C for t > 20 mm and consider post-weld stress relief at 550–650 °C.
Can E335 be formed, bent or molded?
Hot forge at 1100–850 °C then normalize; cold bending needs generous radii (≥3t) and is best done in the annealed condition.
What surface finishes work on E335?
No inherent corrosion resistance — phosphate + oil, zinc plating, hot-dip galvanizing (watch hydrogen embrittlement on hardened parts) or paint; polishes to a bright but non-durable finish.
E335 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 E335; mills typically supply 0.40–0.50 % C (as in 45 / C45 / St60-2) | ≈ 0.45 | 0.45 |
| Sinot specified in EN 10025-2; typical mill practice | ≤ 0.4 | 0.25 |
| Mnnot specified in EN 10025-2; typical mill practice | 0.5 – 0.9 | 0.7 |
| PEN 10025-2 ladle analysis, long products | ≤ 0.05 | 0.02 |
| SEN 10025-2 ladle analysis, long products | ≤ 0.05 | 0.02 |
| NEN 10025-2; limit may be exceeded if N-binding elements present | ≤ 0.01 | 0.01 |
| CuEN 10025-2 | ≤ 0.55 | 0.2 |
| Fe | balance | — |
E335 QT-34-38HRC — frequently asked
What is E335 QT-34-38HRC used for?
E335 QT-34-38HRC is typically used for shafts and axles, bolts and studs, gears, couplings and machine tool components. In short: stronger than structural grades; through-hardenable to 38 HRC; low-cost shaft steel.
What is the yield strength of E335 QT-34-38HRC?
E335 QT-34-38HRC has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 88% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is E335 QT-34-38HRC easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines well with carbide at ~120–180 m/min in the hot-rolled or annealed state; above 30 HRC drop speed and use rigid setups and coolant.
Can E335 QT-34-38HRC be welded?
Not readily — weldability is rated poor (22/100). Weldable but crack-sensitive: CEV ≈ 0.55–0.65, so use low-hydrogen consumables, preheat 150–250 °C for t > 20 mm and consider post-weld stress relief at 550–650 °C.
What surface finishes work on E335 QT-34-38HRC?
No inherent corrosion resistance — phosphate + oil, zinc plating, hot-dip galvanizing (watch hydrogen embrittlement on hardened parts) or paint; polishes to a bright but non-durable finish.
Can E335 QT-34-38HRC be formed, bent or molded?
Hot forge at 1100–850 °C then normalize; cold bending needs generous radii (≥3t) and is best done in the annealed condition.
What is the maximum service temperature of E335 QT-34-38HRC?
E335 QT-34-38HRC 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.
Sources
- EN 10025-2 Hot rolled products of structural steels — Non-alloy structural steels — CEN (2019)
- EN 10277-2 Bright steel products — Steels for general engineering purposes — CEN (2008)
- DIN 17100 St 60-2 (withdrawn, predecessor grade) — DIN (1980)
- 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)
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.