Steel HC340LA · supply condition · default condition
Steel HC340LA-HR
Properties of the HR condition, compared with the other HC340LA tempers.
Choose for thicker gauges (>3 mm) and chassis/wheel parts where hot-rolled surface and lower cost are acceptable.
What is HC340LA-HR?
HC340LA-HR is HC340LA supplied in the HR condition — choose for thicker gauges (>3 mm) and chassis/wheel parts where hot-rolled surface and lower cost are acceptable. HC340LA-HR has a yield strength of 370 MPa (53.7 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 70% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi). HC340LA-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,500°C (2,732 °F).
Advantages
- Readily welded — 88/100, better than 87% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 77% of steel grades
HC340LA-HR properties
Typical room-temperature values for HC340LA-HR — 7 properties are specific to this condition; the rest are grade-level values shared by every HC340LA temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
HC340LA-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,500°C (2,732 °F).
Mechanical13
HC340LA-HR has a yield strength of 370 MPa (53.7 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 70% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
HC340LA-HR is rated for continuous service to 300°C (572 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
HC340LA-HR conducts electricity at 9.5 % IACS, better than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of HC340LA-HR takes about 25 MJ of energy and emits 2.3 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
HC340LA-HR's machinability is good (58/100, better than 75% of steel grades); weldability excellent (88/100); formability good (58/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other HC340LA tempers and conditions
HC340LA is also supplied in 4 other conditions. The full side-by-side table is on the HC340LA overview.
- HRDefaultChoose for thicker gauges (>3 mm) and chassis/wheel parts where hot-rolled surface and lower cost are acceptable.370 MPa yield · 138 HB
- CRStandard stocked form: cold-rolled uncoated HSLA sheet/coil for stamped structural parts that will be phosphated and e-coated.375 MPa yield · 140 HB
- GalvanizedPick when the stamped part sees road salt or moisture and cannot be fully e-coated; zinc gives sacrificial protection at slightly lower formability.375 MPa yield · 140 HB
Working with HC340LA-HR
Is HC340LA easy to machine?
Machines like low-carbon steel but gummy: sharp tools, positive rake and good chip evacuation; mostly blanked/laser-cut rather than machined.
Can HC340LA be welded?
Excellent — low carbon equivalent suits resistance spot, MAG (ER70S-6) and laser welding with no preheat; keep heat input moderate to preserve HAZ strength.
Can HC340LA be formed, bent or molded?
Cold stamps and roll-forms well, but n and r values are below DC04 — allow larger bend radii, expect noticeable springback and design for ~20 % less stretch than mild steel.
What surface finishes work on HC340LA?
Not anodizable; use hot-dip or electro-galvanizing, zinc-phosphate + cathodic e-coat, or powder paint for corrosion protection.
HC340LA 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 |
|---|---|---|
| CEN 10268 max | ≤ 0.1 | 0.07 |
| Si | ≤ 0.5 | 0.15 |
| Mn | ≤ 1 | 0.7 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| Altotal Al, deoxidation | ≥ 0.02 | 0.04 |
| Nbmicroalloy | ≤ 0.09 | 0.03 |
| Timicroalloy | ≤ 0.15 | 0.02 |
| Fe | balance | — |
HC340LA-HR — frequently asked
What is HC340LA-HR used for?
HC340LA-HR is typically used for automotive body panels, stamped chassis reinforcements, seat frames and seat rails, subframe reinforcement plates, steel wheel discs and body cross members. In short: standard HSLA sheet.
What is the yield strength of HC340LA-HR?
HC340LA-HR has a typical yield strength of 370 MPa (53.7 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 70% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is HC340LA-HR easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machines like low-carbon steel but gummy: sharp tools, positive rake and good chip evacuation; mostly blanked/laser-cut rather than machined.
Can HC340LA-HR be welded?
Yes — weldability is rated excellent (88/100). Excellent — low carbon equivalent suits resistance spot, MAG (ER70S-6) and laser welding with no preheat; keep heat input moderate to preserve HAZ strength.
What surface finishes work on HC340LA-HR?
Not anodizable; use hot-dip or electro-galvanizing, zinc-phosphate + cathodic e-coat, or powder paint for corrosion protection.
Can HC340LA-HR be formed, bent or molded?
Cold stamps and roll-forms well, but n and r values are below DC04 — allow larger bend radii, expect noticeable springback and design for ~20 % less stretch than mild steel.
What is the maximum service temperature of HC340LA-HR?
HC340LA-HR is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between HC340LA-HR and HC340LA TMCP?
HR is the default condition — choose for thicker gauges (>3 mm) and chassis/wheel parts where hot-rolled surface and lower cost are acceptable. TMCP: mill route giving finer ferrite grain and better low-temperature toughness/weldability at the same strength class; specify for welded chassis structures. Yield strength is 370 MPa in HR versus 385 MPa in TMCP.
Can FabDigit make parts in HC340LA-HR?
Yes — HC340LA-HR is available for sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- EN 10268 — Cold rolled steel flat products with high yield strength for cold forming — CEN (2013)
- EN 10346 — Continuously hot-dip coated steel flat products for cold forming — CEN (2015)
- EN 10152 — Electrolytically zinc coated cold rolled steel flat products — CEN (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Automotive HSLA cold-rolled and galvanized grades (HC/HX xxxLA) — ArcelorMittal / voestalpine / Baosteel (2023)
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.