Aluminum 4643-O (Annealed)
Temper
AA 4643 · UNS A94643 · EN AW-4643, AW 4643 · JIS A4643
Soft annealed wire/rod, chosen when maximum ductility for coiling or hand feeding is required.
Values for the O condition
Other 4643 tempers and conditions
4643 is listed in 4 conditions; see the grade overview at 4643.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OThis page Annealed | Soft annealed wire/rod, chosen when maximum ductility for coiling or hand feeding is required. | 50 | 130 | 22 | 35 HB | 42 % IACS |
As fabricated | Standard supply condition for ER4643 spooled MIG wire and R4643 TIG rod. | 70 | 165 | 15 | 45 HB | 41 % IACS |
As-welded deposit | Typical all-weld-metal properties when the joint is left in the as-welded condition. | 75 | 170 | 12 | 48 HB | 40 % IACS |
weld deposit solution heat treated and artificially aged after welding | Choose when the whole weldment is post-weld solution treated and aged — the reason 4643 exists instead of 4043. | 195 | 270 | 8 | 80 HB | 39 % IACS |
What is 4643-O?
4643-O is 4643 in the O temper — soft annealed wire/rod, chosen when maximum ductility for coiling or hand feeding is required. 4643-O has a yield strength of 50 MPa (7.25 ksi) and a tensile strength of 130 MPa (18.9 ksi) — weaker than 95% of aluminum grades. Elongation at break is 22% and the elastic modulus is 69 GPa (10 Msi). 4643-O has a density of 2.69 g/cm³ (0.0972 lb/in³), lighter than 67% of aluminum grades. It melts at 574°C (1,065 °F).
Advantages
- Readily welded — 96/100, better than 100% of aluminum grades
- Ductile — tolerates forming and impact — 22%, better than 91% of aluminum grades
- Forms and bends easily — 85/100, better than 91% of aluminum grades
- Conducts heat well — 170 W/m·K (98.2 BTU/hr·ft·°F), better than 82% of aluminum grades
- High electrical conductivity — 42 % IACS, better than 81% of aluminum grades
Limitations
- Low strength — 50 MPa (7.25 ksi), worse than 95% of aluminum grades
- Difficult to machine — 30/100, worse than 92% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
4643-O properties
Typical room-temperature values for 4643-O; 17 are specific to this condition. Other listed values are 4643 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
4643-O has a density of 2.69 g/cm³ (0.0972 lb/in³), lighter than 67% of aluminum grades. It melts at 574°C (1,065 °F).
Mechanical10
4643-O has a yield strength of 50 MPa (7.25 ksi) and a tensile strength of 130 MPa (18.9 ksi) — weaker than 95% of aluminum grades. Elongation at break is 22% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
4643-O is rated for continuous service to 150°C (302 °F). It conducts heat at 170 W/m·K (98.2 BTU/hr·ft·°F), better than 82% of aluminum grades. Thermal expansion is 22 µm/m·K (12.2 µin/in·°F).
Electrical3
4643-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 4643-O takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 20%.
Manufacturability8
4643-O's machinability is poor (30/100, worse than 92% of aluminum grades); weldability excellent (96/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4643-O
Is 4643 easy to machine?
Rarely machined; deposits are soft and gummy — use sharp polished-flute carbide, high speed, low feed and generous lubrication to avoid built-up edge.
Can 4643 be welded?
Purpose-made GMAW/GTAW filler for 6000-series alloys; keep interpass temperature low, clean oxide thoroughly, and specify 4643 only when a post-weld solution + age cycle is planned (otherwise 4043 or 5356 is cheaper).
Can 4643 be formed, bent or molded?
Supplied as drawn wire/rod; good drawability in O temper, and the alloy is fluid enough to cast small remelt shapes if needed.
What surface finishes work on 4643?
Anodizes fair — film is lighter than 4043 and closer to 6061 base metal, but weld beads still shade grey; chemical conversion coating or paint gives the most uniform appearance.
4643 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 | 3.6 – 4.6 | 4.1 |
| Mgaddition vs 4043 that enables post-weld T6 strengthening | 0.1 – 0.3 | 0.2 |
| Fe | ≤ 0.8 | — |
| Cu | ≤ 0.1 | — |
| Mn | ≤ 0.05 | — |
| Zn | ≤ 0.1 | — |
| Ti | ≤ 0.15 | — |
| Bemax, where restricted by AWS A5.10 | ≤ 8×10⁻⁴ | — |
| Others (each)each | ≤ 0.05 | — |
| Others (total)total | ≤ 0.15 | — |
| Al | balance | — |
4643-O — frequently asked
What is 4643-O used for?
4643-O is typically used for filler wire for 6061 weldments, 6063 extrusion joints, 6082 structural welds, weldments given a post-weld solution and ageing cycle, repair welds on heat-treated 6000-series extrusions and forgings and small remelt cast shapes. In short: heat-treatable filler wire.
What is the yield strength of 4643-O?
4643-O has a typical yield strength of 50 MPa (7.25 ksi) and a tensile strength of 130 MPa (18.9 ksi) — weaker than 95% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is 4643-O easy to machine?
Not especially — machinability is rated poor (30/100, worse than 92% of aluminum grades). Rarely machined; deposits are soft and gummy — use sharp polished-flute carbide, high speed, low feed and generous lubrication to avoid built-up edge.
Can 4643-O be welded?
Yes — weldability is rated excellent (96/100). Purpose-made GMAW/GTAW filler for 6000-series alloys; keep interpass temperature low, clean oxide thoroughly, and specify 4643 only when a post-weld solution + age cycle is planned (otherwise 4043 or 5356 is cheaper).
What surface finishes work on 4643-O?
Anodizes fair — film is lighter than 4043 and closer to 6061 base metal, but weld beads still shade grey; chemical conversion coating or paint gives the most uniform appearance.
Can 4643-O be formed, bent or molded?
Supplied as drawn wire/rod; good drawability in O temper, and the alloy is fluid enough to cast small remelt shapes if needed.
What is the maximum service temperature of 4643-O?
4643-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 4643-O?
Yes — 4643-O is available for CNC machining and 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
- AWS A5.10/A5.10M — Specification for Bare Aluminum and Aluminum-Alloy Welding Electrodes and Rods — AWS (2021)
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- EN ISO 18273 — Welding consumables: wire and rods for fusion welding of aluminium and aluminium alloys — CEN/ISO (2015)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (aluminium filler metal selection) — ASM International (1993)
- Aluminium filler metal selection guides (ER4643 / R4643) — Welding consumable producers (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.