Aluminum 4343 · temper
Aluminum 4343-O
Properties of the O condition, compared with the other 4343 tempers.
Standard stocked condition for braze filler sheet/foil and clad brazing sheet blanks that must be deep drawn or formed before brazing.
What is 4343-O?
4343-O is 4343 in the O temper — standard stocked condition for braze filler sheet/foil and clad brazing sheet blanks that must be deep drawn or formed before brazing. 4343-O has a yield strength of 55 MPa (7.98 ksi) and a tensile strength of 130 MPa (18.9 ksi) — weaker than 94% of aluminum grades. Elongation at break is 20% and the elastic modulus is 69 GPa (10 Msi). 4343-O has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 577°C (1,071 °F).
Advantages
- Ductile — tolerates forming and impact — 20%, better than 89% of aluminum grades
- Conducts heat well — 180 W/m·K (104 BTU/hr·ft·°F), better than 87% of aluminum grades
- Forms and bends easily — 70/100, better than 83% of aluminum grades
- High electrical conductivity — 42 % IACS, better than 81% of aluminum grades
Limitations
- Low strength — 55 MPa (7.98 ksi), worse than 94% of aluminum grades
- Difficult to machine — 28/100, worse than 94% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
4343-O properties
Typical room-temperature values for 4343-O — 11 properties are specific to this condition; the rest are grade-level values shared by every 4343 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
4343-O has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 577°C (1,071 °F).
Mechanical10
4343-O has a yield strength of 55 MPa (7.98 ksi) and a tensile strength of 130 MPa (18.9 ksi) — weaker than 94% of aluminum grades. Elongation at break is 20% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
4343-O is rated for continuous service to 150°C (302 °F). It conducts heat at 180 W/m·K (104 BTU/hr·ft·°F), better than 87% of aluminum grades. Thermal expansion is 21.6 µm/m·K (12 µin/in·°F).
Electrical3
4343-O conducts electricity at 42 % IACS, better than 81% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), better than 67% of aluminum grades.
Sustainability4
Producing a kilogram of 4343-O takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
4343-O's machinability is poor (28/100, worse than 94% of aluminum grades); weldability good (55/100); formability very good (70/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 4343 tempers and conditions
4343 is also supplied in 3 other conditions. The full side-by-side table is on the 4343 overview.
- H14Choose for braze foil/shim and clad sheet needing extra stiffness and flatness in handling, with only light forming.165 MPa yield · 52 HB
- H24Pick when H14-level strength is needed but bending/forming ductility must be preserved (typical for clad brazing strip).145 MPa yield · 48 HB
- OStandard stocked condition for braze filler sheet/foil and clad brazing sheet blanks that must be deep drawn or formed before brazing.55 MPa yield · 40 HB
Working with 4343-O
Is 4343 easy to machine?
Soft and gummy with abrasive Si particles — use polished high-rake carbide, high speed, flood lubricant to avoid built-up edge; rarely machined as a structural part.
Can 4343 be welded?
Primarily a filler/cladding alloy: excellent flow in CAB (NOCOLOK) and vacuum brazing at 590–610 °C; as a base metal it is weak and hot-short, so joints are made by brazing rather than fusion welding.
Can 4343 be formed, bent or molded?
O and H2x tempers roll and draw well as clad layers; keep total cold work low in H1x tempers and avoid tight bends where Si particles nucleate cracks.
What surface finishes work on 4343?
Anodizing gives dark, blotchy films (avoid for cosmetics); chemical conversion coating or painting after brazing, and flux residues must be washed off to prevent staining.
4343 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 |
|---|---|---|
| Siprovides low melting range for brazing | 6.8 – 8.2 | 7.5 |
| Fe | ≤ 0.8 | 0.35 |
| Cu | ≤ 0.25 | — |
| Mn | ≤ 0.1 | — |
| Zn | ≤ 0.2 | — |
| Others (each)per AA limits | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
4343-O — frequently asked
What is 4343-O used for?
4343-O is typically used for brazing sheet cladding for heat exchangers, radiator and charge-air cooler tube stock, evaporator and condenser plates, brazing filler wire and rod, brazing shim and preforms and oil cooler assemblies. In short: brazing clad alloy; 7% Si skin.
What is the yield strength of 4343-O?
4343-O has a typical yield strength of 55 MPa (7.98 ksi) and a tensile strength of 130 MPa (18.9 ksi) — weaker than 94% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is 4343-O easy to machine?
Not especially — machinability is rated poor (28/100, worse than 94% of aluminum grades). Soft and gummy with abrasive Si particles — use polished high-rake carbide, high speed, flood lubricant to avoid built-up edge; rarely machined as a structural part.
Can 4343-O be welded?
Yes — weldability is rated good (55/100). Primarily a filler/cladding alloy: excellent flow in CAB (NOCOLOK) and vacuum brazing at 590–610 °C; as a base metal it is weak and hot-short, so joints are made by brazing rather than fusion welding.
What surface finishes work on 4343-O?
Anodizing gives dark, blotchy films (avoid for cosmetics); chemical conversion coating or painting after brazing, and flux residues must be washed off to prevent staining.
Can 4343-O be formed, bent or molded?
O and H2x tempers roll and draw well as clad layers; keep total cold work low in H1x tempers and avoid tight bends where Si particles nucleate cracks.
What is the maximum service temperature of 4343-O?
4343-O is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 4343-O?
Yes — 4343-O is available for sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- EN 573-3 Aluminium and aluminium alloys — Chemical composition — CEN (2019)
- ASM Handbook Vol. 2: Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 6: Welding, Brazing and Soldering (aluminium brazing) — ASM International (1993)
- Aluminium brazing sheet (3003 core / 4343 clad) product data — Constellium / Granges (2022)
- MatWeb aluminium 4343 alloy entries — MatWeb LLC (2024)
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.