Steel HC300LA +ZM
Finish state
EN HC300LA
+ZM = zinc-magnesium-aluminium coated
Use where equal corrosion life is wanted at reduced coating weight, e.g. underbody and chassis parts.
Values for the +ZM condition
Other HC300LA tempers and conditions
HC300LA is listed in 5 conditions; see the grade overview at HC300LA.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
CRDefault Cold rolled | Standard bare cold-rolled coil/blank for structural stampings that are subsequently phosphated and e-coated. | 335 | 420 | 28 | 130 HB | — |
Electrolytically zinc coated | Choose for good surface appearance and moderate corrosion protection on visible or painted structural parts. | 335 | 420 | 27 | 130 HB | 10 % IACS |
Hot-dip galvanized | Highest-volume coated form for automotive body-in-white and chassis brackets needing cathodic protection. | 335 | 420 | 26 | 130 HB | 10 % IACS |
+ZMThis page Zinc-magnesium-aluminium coated | Use where equal corrosion life is wanted at reduced coating weight, e.g. underbody and chassis parts. | 335 | 420 | 26 | 130 HB | 10 % IACS |
Galvannealed zinc-iron coating | Pick when superior paint adhesion and spot-weldability are needed; coating is more brittle in severe draws. | 340 | 425 | 25 | 132 HB | 10 % IACS |
What is HC300LA +ZM?
HC300LA +ZM is HC300LA supplied in the +ZM condition — use where equal corrosion life is wanted at reduced coating weight, e.g. underbody and chassis parts. HC300LA +ZM has a yield strength of 335 MPa (48.6 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 77% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi). HC300LA +ZM has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,495°C (2,723 °F). CR is the default condition FabDigit quotes; +ZM is available on request or by drawing note.
Advantages
- Good corrosion resistance — 48/100, better than 98% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
- Forms and bends easily — 64/100, better than 79% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
- Low strength — 335 MPa (48.6 ksi), worse than 77% of steel grades
HC300LA +ZM properties
Typical room-temperature values for HC300LA +ZM; 20 are specific to this condition. Other listed values are HC300LA reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
HC300LA +ZM has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,495°C (2,723 °F).
Mechanical12
HC300LA +ZM has a yield strength of 335 MPa (48.6 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 77% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
HC300LA +ZM is rated for continuous service to 200°C (392 °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
HC300LA +ZM conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), better than 98% of steel grades.
Sustainability4
Producing a kilogram of HC300LA +ZM takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability6
HC300LA +ZM's machinability is fair (53/100, better than 53% of steel grades); weldability very good (74/100); formability good (64/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with HC300LA +ZM
Is HC300LA easy to machine?
Rarely machined as sheet; blanking, laser and fine-piercing are preferred — allow larger punch clearance and expect higher blanking loads than DC04.
Can HC300LA be welded?
Excellent for resistance spot, MAG and laser welding thanks to low carbon and CEV; zinc-coated variants need ventilation, higher weld current and gap control.
Can HC300LA be formed, bent or molded?
Good deep-draw and stretch behaviour (n90 ≥ 0.16) but noticeably higher springback than mild steel — compensate die radii and use overbend/post-stretch.
What surface finishes work on HC300LA?
Bare sheet must be phosphated and e-coated or painted quickly; zinc coatings (+ZE/+Z/+ZF/+ZM) take standard automotive paint systems and are readily adhesive-bonded.
HC300LA 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 | 0.06 |
| Si | ≤ 0.5 | 0.1 |
| Mn | ≤ 1 | 0.6 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Altotal Al, min | ≥ 0.02 | 0.04 |
| Nbmicro-alloying | ≤ 0.09 | 0.03 |
| Timicro-alloying | ≤ 0.15 | 0.02 |
| Fe | balance | — |
HC300LA +ZM — frequently asked
What is HC300LA +ZM used for?
HC300LA +ZM is typically used for automotive structural parts, reinforcement panels and chassis brackets. In short: higher-strength HSLA sheet; good spot-weld response; stronger than HC260LA.
What is the yield strength of HC300LA +ZM?
HC300LA +ZM has a typical yield strength of 335 MPa (48.6 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 77% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is HC300LA +ZM easy to machine?
Reasonably — machinability is rated fair (53/100, better than 53% of steel grades). Rarely machined as sheet; blanking, laser and fine-piercing are preferred — allow larger punch clearance and expect higher blanking loads than DC04.
Can HC300LA +ZM be welded?
Yes — weldability is rated very good (74/100). Excellent for resistance spot, MAG and laser welding thanks to low carbon and CEV; zinc-coated variants need ventilation, higher weld current and gap control.
What surface finishes work on HC300LA +ZM?
Bare sheet must be phosphated and e-coated or painted quickly; zinc coatings (+ZE/+Z/+ZF/+ZM) take standard automotive paint systems and are readily adhesive-bonded.
Can HC300LA +ZM be formed, bent or molded?
Good deep-draw and stretch behaviour (n90 ≥ 0.16) but noticeably higher springback than mild steel — compensate die radii and use overbend/post-stretch.
What is the maximum service temperature of HC300LA +ZM?
HC300LA +ZM is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
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)
- HSLA cold-rolled and coated automotive steel product data — ArcelorMittal / thyssenkrupp Steel (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.