Aluminum 1188-H12
Temper
AA 1188 · UNS A91188 · EN Al99.88
H12 = strain hardened, quarter hard
Light cold work for slightly stiffer sheet that still forms and bends well.
Values for the H12 condition
Other 1188 tempers and conditions
1188 is listed in 12 conditions; see the grade overview at 1188.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Pick for maximum formability, conductivity and corrosion resistance — deep drawing, linings, foil stock, reflectors. | 22 | 62 | 45 | 17 HB | 62.5 % IACS |
Slightly strain hardened | Near-O softness with the light work introduced by levelling; common on plate and extruded sections. | 28 | 68 | 38 | 19 HB | 62.3 % IACS |
As fabricated | Hot-worked or extruded stock with no mechanical property limits; use where the part will be annealed or formed afterwards. | 30 | 70 | 32 | 19 HB | 62 % IACS |
Strain hardened and partially annealed, quarter hard | Back-annealed quarter-hard temper: H12-level strength with better ductility for forming. | 52 | 78 | 24 | 22 HB | 62.2 % IACS |
H12This page Strain hardened, quarter hard | Light cold work for slightly stiffer sheet that still forms and bends well. | 58 | 78 | 20 | 22 HB | 62 % IACS |
Strain hardened and partially annealed, half hard | Half-hard sheet with restored bend ductility — the usual choice for formed panels and linings. | 66 | 90 | 16 | 26 HB | 62 % IACS |
Strain hardened, half hard | The usual compromise temper for flat sheet that must hold shape yet still be bent. | 72 | 90 | 12 | 26 HB | 62 % IACS |
Strain hardened and partially annealed, three-quarter hard | Three-quarter hard with partial anneal for strip that must still take a tight roll-form. | 80 | 103 | 10 | 30 HB | 61.8 % IACS |
Strain hardened, three-quarter hard | Higher-strength strip where only mild forming (roll forming, gentle bends) is required. | 88 | 103 | 8 | 30 HB | 61.8 % IACS |
Strain hardened and partially annealed, full hard | Full-hard stabilised strip where slightly better ductility than H18 is needed at similar strength. | 98 | 118 | 6 | 33 HB | 61.5 % IACS |
Strain hardened, full hard | Full-hard strip and foil: highest practical strength for this purity, minimal formability. | 105 | 118 | 5 | 33 HB | 61.5 % IACS |
Strain hardened, extra hard | Extra-hard rolling used mainly for thin capacitor/electrode foil where stiffness and handling strength matter. | 118 | 132 | 3 | 36 HB | 61.3 % IACS |
What is 1188-H12?
1188-H12 is 1188 in the H12 temper — light cold work for slightly stiffer sheet that still forms and bends well. 1188-H12 has a yield strength of 58 MPa (8.41 ksi) and a tensile strength of 78 MPa (11.3 ksi) — weaker than 93% of aluminum grades. Elongation at break is 20% and the elastic modulus is 69 GPa (10 Msi). 1188-H12 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 657°C (1,215 °F). O is the default condition FabDigit quotes; H12 is available on request or by drawing note.
Advantages
- Conducts heat well — 233 W/m·K (134.6 BTU/hr·ft·°F), better than 99% of aluminum grades
- High electrical conductivity — 62 % IACS, better than 99% of aluminum grades
- Polishes to a fine finish — 90/100, better than 98% of aluminum grades
- Readily welded — 92/100, better than 95% of aluminum grades
- Good corrosion resistance — 78/100, better than 94% of aluminum grades
Limitations
- Difficult to machine — 22/100, worse than 98% of aluminum grades
- Low strength — 58 MPa (8.41 ksi), worse than 93% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
1188-H12 properties
Typical room-temperature values for 1188-H12; 11 are specific to this condition. Other listed values are 1188 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
1188-H12 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 657°C (1,215 °F).
Mechanical10
1188-H12 has a yield strength of 58 MPa (8.41 ksi) and a tensile strength of 78 MPa (11.3 ksi) — weaker than 93% of aluminum grades. Elongation at break is 20% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
1188-H12 is rated for continuous service to 120°C (248 °F). It conducts heat at 233 W/m·K (134.6 BTU/hr·ft·°F), better than 99% of aluminum grades. Thermal expansion is 23.6 µm/m·K (13.1 µin/in·°F).
Electrical3
1188-H12 conducts electricity at 62 % IACS, better than 99% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 94% of aluminum grades.
Sustainability4
Producing a kilogram of 1188-H12 takes about 215 MJ of energy and emits 13.5 kg of CO₂ — more than 93% of aluminum grades. Typical recycled content is 0%.
Manufacturability8
1188-H12's machinability is poor (22/100, worse than 98% of aluminum grades); weldability excellent (92/100); formability excellent (88/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1188-H12
Is 1188 easy to machine?
Very soft and gummy — use polished high-rake carbide, high speed, flood coolant or mist and generous chip clearance to avoid built-up edge; cold-worked H1x tempers cut noticeably cleaner than O.
Can 1188 be welded?
Excellent by TIG/MIG and resistance welding with 1100 or matching 1188 filler; the weld and HAZ revert to O-temper strength, so design joints for annealed properties.
Can 1188 be formed, bent or molded?
Outstanding cold formability in O/H111 — deep drawing, spinning, tight bends and rolling down to thin foil; springback is minimal but the surface marks easily.
What surface finishes work on 1188?
Ideal for bright and clear anodising and chemical/electro-brightening thanks to the low Fe/Si; polishes to a high specular reflectance, and takes conversion coatings and paint after standard alkaline etch/desmut.
1188 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 |
|---|---|---|
| Si | ≤ 0.06 | 0.03 |
| Fe | ≤ 0.06 | 0.04 |
| Cukept very low for corrosion resistance | ≤ 0.01 | 0 |
| Mn | ≤ 0.01 | — |
| Mg | ≤ 0.01 | — |
| Zn | ≤ 0.03 | — |
| Ti | ≤ 0.01 | — |
| VV+Ti often limited jointly | ≤ 0.05 | — |
| Ga | ≤ 0.03 | — |
| Others (each) | ≤ 0.01 | — |
| Al99.88 % Al minimum by difference | ≥ 99.88 (balance) | — |
1188-H12 — frequently asked
What is 1188-H12 used for?
1188-H12 is typically used for electrolytic capacitor foil, high-purity chemical processing equipment, reflectors and specialty electrical conductors. In short: highest-purity 1000-series stock; best bright-anodizing aluminum; 62.5% IACS conductivity.
What is the yield strength of 1188-H12?
1188-H12 has a typical yield strength of 58 MPa (8.41 ksi) and a tensile strength of 78 MPa (11.3 ksi) — weaker than 93% of aluminum grades. Strength varies by condition: see the 12 listed tempers.
Is 1188-H12 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 98% of aluminum grades). Very soft and gummy — use polished high-rake carbide, high speed, flood coolant or mist and generous chip clearance to avoid built-up edge; cold-worked H1x tempers cut noticeably cleaner than O.
Can 1188-H12 be welded?
Yes — weldability is rated excellent (92/100). Excellent by TIG/MIG and resistance welding with 1100 or matching 1188 filler; the weld and HAZ revert to O-temper strength, so design joints for annealed properties.
What surface finishes work on 1188-H12?
Ideal for bright and clear anodising and chemical/electro-brightening thanks to the low Fe/Si; polishes to a high specular reflectance, and takes conversion coatings and paint after standard alkaline etch/desmut.
Can 1188-H12 be formed, bent or molded?
Outstanding cold formability in O/H111 — deep drawing, spinning, tight bends and rolling down to thin foil; springback is minimal but the surface marks easily.
What is the maximum service temperature of 1188-H12?
1188-H12 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.
What is the difference between 1188-O and 1188-H19?
O is the default condition — pick for maximum formability, conductivity and corrosion resistance — deep drawing, linings, foil stock, reflectors. H19: extra-hard rolling used mainly for thin capacitor/electrode foil where stiffness and handling strength matter. Yield strength is 22 MPa in O versus 118 MPa in H19.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys (Teal Sheets) — The Aluminum Association (2018)
- ASTM B209 / B209M — Aluminum and Aluminum-Alloy Sheet and Plate — ASTM International (2021)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
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.