Aluminum 6023-T4
Temper
AA 6023 · EN AlSi1Sn1MgBi
T4 = solution heat treated and naturally aged
Intermediate strength with better ductility; used when parts are formed or staked after machining and later aged to T6.
Values for the T4 condition
Other 6023 tempers and conditions
6023 is listed in 8 conditions; see the grade overview at 6023.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for heavy cold forming, deep drilling or re-heat-treatment; not a normal stock condition for this alloy. | 80 | 150 | 22 | 45 HB | 49 % IACS |
T4This page Solution heat treated and naturally aged | Intermediate strength with better ductility; used when parts are formed or staked after machining and later aged to T6. | 145 | 250 | 18 | 68 HB | 37 % IACS |
T6Default Solution heat treated and artificially aged | Standard stocked condition for automatic-lathe bar: peak strength with short, well-broken chips. | 295 | 330 | 10 | 100 HB | 40 % IACS |
T6, stress relieved by stretching | Choose when tight dimensional stability after heavy stock removal is required from plate or drawn bar. | 300 | 330 | 10 | 100 HB | 40 % IACS |
Solution treated, stretched, artificially aged, no further straightening | Extruded bar/profile with residual stress relieved by stretching and no post-stretch straightening — best distortion control for long machined parts. | 300 | 330 | 10 | 100 HB | 40 % IACS |
T6, stress relieved by stretching, minor straightening | Most common extruded free-machining bar condition: stress-relieved, straight, ready for CNC/screw-machine work. | 300 | 330 | 10 | 100 HB | 40 % IACS |
Solution heat treated, cold worked and artificially aged | Cold-drawn-then-aged bar for higher strength and even better surface finish/chip control than T6. | 350 | 375 | 8 | 110 HB | 41 % IACS |
Solution heat treated, artificially aged and cold worked | Highest-strength, close-tolerance cold-finished bar for high-volume screw-machine parts needing maximum surface quality. | 380 | 400 | 6 | 120 HB | 41 % IACS |
What is 6023-T4?
6023-T4 is 6023 in the T4 temper — intermediate strength with better ductility; used when parts are formed or staked after machining and later aged to T6. 6023-T4 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 68% of aluminum grades. Elongation at break is 18% and the elastic modulus is 69.5 GPa (10.1 Msi). 6023-T4 has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 575°C (1,067 °F). T6 is the default condition FabDigit quotes; T4 is available on request or by drawing note.
Advantages
- Easy to machine — 80/100, better than 92% of aluminum grades
- Ductile — tolerates forming and impact — 18%, better than 86% of aluminum grades
Limitations
- Difficult to weld — 25/100, worse than 76% of aluminum grades
6023-T4 properties
Typical room-temperature values for 6023-T4; 10 are specific to this condition. Other listed values are 6023 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
6023-T4 has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 575°C (1,067 °F).
Mechanical13
6023-T4 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 68% of aluminum grades. Elongation at break is 18% and the elastic modulus is 69.5 GPa (10.1 Msi).
Thermal6
6023-T4 is rated for continuous service to 150°C (302 °F). It conducts heat at 155 W/m·K (89.6 BTU/hr·ft·°F), better than 71% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
6023-T4 conducts electricity at 37 % IACS, better than 58% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), better than 62% of aluminum grades.
Sustainability4
Producing a kilogram of 6023-T4 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability7
6023-T4's machinability is very good (80/100, better than 92% of aluminum grades); weldability poor (25/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 6023-T4
Is 6023 easy to machine?
Excellent — run at high spindle speed with polished-flute carbide, light lubrication; Sn/Bi phases break chips into short curls so deep drilling and Swiss-turning need no chip-breaker geometry.
Can 6023 be welded?
Poor — low-melting Sn/Bi films cause hot cracking and weak fusion zones; use mechanical joints, adhesives or friction/resistance methods instead of MIG/TIG.
Can 6023 be formed, bent or molded?
Extrude and cold-draw in the soft or T4 condition; bending in T6 requires generous radii (>3t) and heavy cold forming risks tearing at the second-phase particles.
What surface finishes work on 6023?
Takes clear and coloured sulphuric anodizing well (main advantage over 2011); bright/decorative anodizing may show slight grey speckle, and electroless-nickel or chromate conversion coatings work normally.
6023 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 |
|---|---|---|
| Siwith Mg forms the Mg2Si strengthening phase | 0.7 – 1.3 | 1 |
| Mg | 0.6 – 1.2 | 0.9 |
| Snprimary free-machining (chip-breaking) addition, lead substitute | 0.6 – 1.4 | 1 |
| Bisecondary free-machining addition | 0.2 – 0.8 | 0.5 |
| Feimpurity limit | ≤ 0.5 | 0.25 |
| Cu | ≤ 0.2 | 0.05 |
| Mn | ≤ 0.3 | 0.05 |
| Cr | ≤ 0.15 | 0.03 |
| Zn | ≤ 0.2 | 0.05 |
| Tigrain refiner | ≤ 0.1 | 0.02 |
| Pbkept low for RoHS/ELV lead-free status | ≤ 0.05 | 0 |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Albalance; verify exact limits against the current AA Teal Sheets / EN 573-3 registration for EN AW-6023 | balance | — |
6023-T4 — frequently asked
What is 6023-T4 used for?
6023-T4 is typically used for precision turned parts, electrical and RF connector bodies, screw machine fittings, swiss-turned pins and spacers, deep-drilled manifold blocks and anodized instrument components. In short: lead-free free-machining alloy; anodizes better than 2011; poor fusion weldability.
What is the yield strength of 6023-T4?
6023-T4 has a typical yield strength of 145 MPa (21 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 68% of aluminum grades. Strength varies by condition: see the 8 listed tempers.
Is 6023-T4 easy to machine?
Yes — machinability is rated very good (80/100, better than 92% of aluminum grades). Excellent — run at high spindle speed with polished-flute carbide, light lubrication; Sn/Bi phases break chips into short curls so deep drilling and Swiss-turning need no chip-breaker geometry.
Can 6023-T4 be welded?
Not readily — weldability is rated poor (25/100). Poor — low-melting Sn/Bi films cause hot cracking and weak fusion zones; use mechanical joints, adhesives or friction/resistance methods instead of MIG/TIG.
What surface finishes work on 6023-T4?
Takes clear and coloured sulphuric anodizing well (main advantage over 2011); bright/decorative anodizing may show slight grey speckle, and electroless-nickel or chromate conversion coatings work normally.
Can 6023-T4 be formed, bent or molded?
Extrude and cold-draw in the soft or T4 condition; bending in T6 requires generous radii (>3t) and heavy cold forming risks tearing at the second-phase particles.
What is the maximum service temperature of 6023-T4?
6023-T4 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.
What is the difference between 6023-T6 and 6023-O?
T6 is the default condition — standard stocked condition for automatic-lathe bar: peak strength with short, well-broken chips. O: softest condition for heavy cold forming, deep drilling or re-heat-treatment; not a normal stock condition for this alloy. Yield strength is 295 MPa in T6 versus 80 MPa in O.
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 (EN AW-6023 AlSi1Sn1MgBi) — CEN (2019)
- EN 755-2 Aluminium extruded rod/bar — Mechanical properties — CEN (2016)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Lead-free free-machining aluminium bar (Sn/Bi modified 6000 series) technical data — European extruder datasheets (2022)
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.