Steel HC340LA TMCP
Supply condition
EN HC340LA
TMCP = thermomechanically controlled processed
Mill route giving finer ferrite grain and better low-temperature toughness/weldability at the same strength class; specify for welded chassis structures.
Values for the TMCP condition
Other HC340LA tempers and conditions
HC340LA is listed in 3 conditions; see the grade overview at HC340LA.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HRDefault Hot rolled | Choose for thicker gauges (>3 mm) and chassis/wheel parts where hot-rolled surface and lower cost are acceptable. | 370 | 460 | 26 | 138 HB | 9.5 % IACS |
Cold rolled | Standard stocked form: cold-rolled uncoated HSLA sheet/coil for stamped structural parts that will be phosphated and e-coated. | 375 | 455 | 25 | 140 HB | 9.5 % IACS |
TMCPThis page Thermomechanically controlled processed | Mill route giving finer ferrite grain and better low-temperature toughness/weldability at the same strength class; specify for welded chassis structures. | 385 | 470 | 27 | 145 HB | 9.5 % IACS |
What is HC340LA TMCP?
HC340LA TMCP is HC340LA supplied in the TMCP condition — mill route giving finer ferrite grain and better low-temperature toughness/weldability at the same strength class; specify for welded chassis structures. HC340LA TMCP has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 65% of steel grades. Elongation at break is 27% and the elastic modulus is 210 GPa (30.5 Msi). HC340LA TMCP 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). HR is the default condition FabDigit quotes; TMCP is available on request or by drawing note.
Advantages
- Readily welded — 90/100, better than 90% of steel grades
- Ductile — tolerates forming and impact — 27%, better than 86% of steel grades
- Forms and bends easily — 64/100, better than 79% of steel grades
- High electrical conductivity — 9.5 % IACS, better than 75% of steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
HC340LA TMCP properties
Typical room-temperature values for HC340LA TMCP; 21 are specific to this condition. Other listed values are HC340LA reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
HC340LA TMCP 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).
Mechanical14
HC340LA TMCP has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 65% of steel grades. Elongation at break is 27% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
HC340LA TMCP is rated for continuous service to 300°C (572 °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
HC340LA TMCP conducts electricity at 9.5 % IACS, better than 75% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of HC340LA TMCP 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 TMCP's machinability is good (56/100, better than 71% of steel grades); weldability excellent (90/100); formability good (64/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with HC340LA TMCP
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 TMCP — frequently asked
What is HC340LA TMCP used for?
HC340LA TMCP 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 TMCP?
HC340LA TMCP has a typical yield strength of 385 MPa (55.8 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 65% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is HC340LA TMCP easy to machine?
Reasonably — machinability is rated good (56/100, better than 71% 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 TMCP be welded?
Yes — weldability is rated excellent (90/100). 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 TMCP?
Not anodizable; use hot-dip or electro-galvanizing, zinc-phosphate + cathodic e-coat, or powder paint for corrosion protection.
Can HC340LA TMCP 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 TMCP?
HC340LA TMCP 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 TMCP?
Yes — HC340LA TMCP is available for sheet metal; every part is priced by an engineer rather than instantly. 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.