Aluminum 3103 · temper
Aluminum 3103-H18
Properties of the H18 condition, compared with the other 3103 tempers.
Maximum work-hardened strength; flat parts, spacers and roll-formed strip with no tight bending.
What is 3103-H18?
3103-H18 is 3103 in the H18 temper — maximum work-hardened strength; flat parts, spacers and roll-formed strip with no tight bending. 3103-H18 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 54% of aluminum grades. Elongation at break is 3% and the elastic modulus is 69 GPa (10 Msi). 3103-H18 has a density of 2.73 g/cm³ (0.0986 lb/in³), heavier than 61% of aluminum grades. It melts at 645°C (1,193 °F).
Advantages
- Readily welded — 90/100, better than 90% of aluminum grades
- Good corrosion resistance — 70/100, better than 79% of aluminum grades
- High electrical conductivity — 41 % IACS, better than 78% of aluminum grades
Limitations
- Limited ductility — 3%, worse than 79% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
3103-H18 properties
Typical room-temperature values for 3103-H18 — 9 properties are specific to this condition; the rest are grade-level values shared by every 3103 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
3103-H18 has a density of 2.73 g/cm³ (0.0986 lb/in³), heavier than 61% of aluminum grades. It melts at 645°C (1,193 °F).
Mechanical11
3103-H18 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 54% of aluminum grades. Elongation at break is 3% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
3103-H18 is rated for continuous service to 120°C (248 °F). It conducts heat at 155 W/m·K (89.6 BTU/hr·ft·°F), better than 71% of aluminum grades. Thermal expansion is 23.2 µm/m·K (12.9 µin/in·°F).
Electrical3
3103-H18 conducts electricity at 41 % IACS, better than 78% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 79% of aluminum grades.
Sustainability4
Producing a kilogram of 3103-H18 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 35%.
Manufacturability7
3103-H18's machinability is fair (45/100, worse than 72% of aluminum grades); weldability excellent (90/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 3103 tempers and conditions
3103 is also supplied in 15 other conditions. The full side-by-side table is on the 3103 overview.
- H18Maximum work-hardened strength; flat parts, spacers and roll-formed strip with no tight bending.180 MPa yield · 54 HB
- H16Higher-strength strip for lightly formed parts, shutters and profiled sheet.155 MPa yield · 48 HB
- H17Heavily cold-worked 3103 just below full hard, giving near-maximum strain-hardened strength with minimal remaining ductility.155 MPa yield · 50 HB
- H15Cold-worked 3103 between half and three-quarter hard, used where higher panel stiffness and dent resistance are needed with limited bending.132 MPa yield · 44 HB
- H14The standard stock temper: balanced strength and bendability for panels, cladding, ducting and general sheet metal.130 MPa yield · 42 HB
- H24Most common European roofing/cladding and bending temper: H14 strength with markedly better bend behaviour.115 MPa yield · 41 HB
- H13Intermediate cold-rolled 3103 between quarter and half hard, balancing moderate strength with useful bending ductility.108 MPa yield · 38 HB
- H12Light work-hardened strip when a bit more stiffness than O is needed but bending is still frequent.105 MPa yield · 37 HB
- H11Lightly cold-worked 3103 sheet just above annealed strength, retaining high formability for deep-drawn and roll-formed parts.75 MPa yield · 32 HB
- FAs-fabricated 3103 with no special control of thermal or strain-hardening history and no guaranteed mechanical limits; properties depend on the forming route.55 MPa yield · 30 HB
- OPick for maximum formability — deep drawing, spinning, tight bends and hydroforming.45 MPa yield · 28 HB
Working with 3103-H18
Is 3103 easy to machine?
Soft and gummy — use polished high-rake carbide, high speeds, low feeds and flood coolant or minimum-quantity lubrication to avoid built-up edge; harder H16/H18 tempers cut cleaner.
Can 3103 be welded?
Excellent with GTAW/GMAW or resistance welding, filler ER1100 or ER4043 (ER5356 where more strength is wanted); the HAZ reverts toward O-temper strength.
Can 3103 be formed, bent or molded?
Very good cold formability, best in O/H22/H24; use generous bend radii in H16–H18 and roll-form rather than press-brake hard tempers.
What surface finishes work on 3103?
Takes protective and hard anodizing well and is a standard pre-painted/coil-coated substrate, but clear anodize looks grey-brown, so bright polish or brush finishes are less attractive than on 5xxx/6xxx.
3103 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 |
|---|---|---|
| Mnprincipal strengthening addition | 0.9 – 1.5 | 1.2 |
| Fe | ≤ 0.7 | 0.45 |
| Si | ≤ 0.5 | 0.25 |
| Mg | ≤ 0.3 | 0.05 |
| Zn | ≤ 0.2 | — |
| Cu | ≤ 0.1 | 0.03 |
| Cr | ≤ 0.1 | — |
| Ti+Zrcombined limit per EN 573-3 | ≤ 0.1 | — |
| Others (each)total others 0.15 max | ≤ 0.05 | — |
| Alremainder, ~97.5% | balance | — |
3103-H18 — frequently asked
What is 3103-H18 used for?
3103-H18 is typically used for roofing sheet, cladding and HVAC ducts. In short: european 3003; forming sheet.
What is the yield strength of 3103-H18?
3103-H18 has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 54% of aluminum grades. Strength varies by condition: see the 16 listed tempers.
Is 3103-H18 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 72% of aluminum grades). Soft and gummy — use polished high-rake carbide, high speeds, low feeds and flood coolant or minimum-quantity lubrication to avoid built-up edge; harder H16/H18 tempers cut cleaner.
Can 3103-H18 be welded?
Yes — weldability is rated excellent (90/100). Excellent with GTAW/GMAW or resistance welding, filler ER1100 or ER4043 (ER5356 where more strength is wanted); the HAZ reverts toward O-temper strength.
What surface finishes work on 3103-H18?
Takes protective and hard anodizing well and is a standard pre-painted/coil-coated substrate, but clear anodize looks grey-brown, so bright polish or brush finishes are less attractive than on 5xxx/6xxx.
Can 3103-H18 be formed, bent or molded?
Very good cold formability, best in O/H22/H24; use generous bend radii in H16–H18 and roll-form rather than press-brake hard tempers.
What is the maximum service temperature of 3103-H18?
3103-H18 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 3103-H18?
Yes — 3103-H18 is available for sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- EN 573-3 — Aluminium and aluminium alloys: chemical composition of wrought products — CEN (2019)
- EN 485-2 — Aluminium sheet, strip and plate: mechanical properties — CEN (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- International Alloy Designations and Chemical Composition Limits (Teal Sheets) — The Aluminum Association (2018)
- EN AW-3103 (AlMn1) rolled sheet/strip datasheets — European rolling mills (Hydro/Constellium-type) (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.