Aluminum ZL203
GB ZL203
ZL203 is a simple Al-Cu sand casting alloy from GB/T 1173, cross-referenced to 295.0 and roughly comparable to ANSI 208.0, with copper as the only significant strengthening addition.
Reference datasheet — ZL203 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the T4 condition
ZL203 tempers and conditions
ZL203 is supplied in 5 conditions, soft to hard. T4 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Low-cost as-cast condition for lightly loaded, dimension-stable parts where machinability matters more than strength. | 95 | 150 | 2.5 | 45 HB | 31 % IACS |
T4Default Solution heat treated and naturally aged | Standard supply condition: best combination of strength and ductility/toughness for general engineering castings. | 110 | 215 | 8 | 60 HB | 33 % IACS |
Solution heat treated and overaged (stabilized) | Overaged for dimensional stability and reduced residual stress on parts running warm or requiring tight machining tolerance. | 150 | 200 | 3 | 68 HB | 37 % IACS |
Cooled from hot working and artificially aged | Choose when higher strength and hardness are needed and 3 % elongation is acceptable. | 155 | 225 | 3 | 70 HB | 35 % IACS |
Solution heat treated and artificially aged | Peak-strength condition used mainly on the ANSI 295.0 equivalent when maximum hardness/wear resistance is required. | 165 | 250 | 5 | 75 HB | 35 % IACS |
What is ZL203?
ZL203 is a simple Al-Cu sand casting alloy from GB/T 1173, cross-referenced to 295.0 and roughly comparable to ANSI 208.0, with copper as the only significant strengthening addition. Strength is modest at 215 MPa tensile, 110 MPa yield, 8 % elongation and 60 HB, but machinability is rated 80 — among the best of the cast aluminum alloys — and thermal conductivity is 138 W/m·K. Service is limited to 120 °C, the alloy is hot-crack sensitive and unsuitable for pressure-tight castings, and anodized films are grey; ZL201 offers higher strength on the same casting routes. ZL203 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 545°C (1,013 °F). ZL203 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 81% of aluminum grades. Elongation at break is 8% and the elastic modulus is 70 GPa (10.2 Msi).
What is ZL203 used for?
- General machinery castings
- Gear housings and covers
- Machine tool brackets and bases
- Fixture and jig bodies
- Non-pressure instrument housings
- Heavily machined prototype castings
Advantages
- Easy to machine — 80/100, better than 92% of aluminum grades
Limitations
- Needs corrosion protection — 35/100, worse than 85% of aluminum grades
- Low strength — 110 MPa (16 ksi), worse than 81% of aluminum grades
- Limited formability — 10/100, worse than 80% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
- Difficult to weld — 25/100, worse than 76% of aluminum grades
ZL203 properties
Typical room-temperature values for ZL203-T4; bars are the position among aluminum grades.
Physical3
ZL203 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 545°C (1,013 °F).
Mechanical12
ZL203 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 81% of aluminum grades. Elongation at break is 8% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal6
ZL203 is rated for continuous service to 120°C (248 °F). It conducts heat at 138 W/m·K (79.7 BTU/hr·ft·°F), worse than 55% of aluminum grades. Thermal expansion is 23 µm/m·K (12.8 µin/in·°F).
Electrical3
ZL203 conducts electricity at 33 % IACS, worse than 57% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (35/100), worse than 85% of aluminum grades.
Sustainability4
Producing a kilogram of ZL203 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
ZL203's machinability is very good (80/100, better than 92% of aluminum grades); weldability poor (25/100); formability not recommended (10/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. ZL203 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZL203
Is ZL203 easy to machine?
Excellent — one of the best-machining cast aluminium alloys; use polished-flute carbide or PCD, high speed, low feed, and flood coolant; T5/T6 gives cleaner surfaces than as-cast.
Can ZL203 be welded?
Poor — Al-Cu is highly hot-crack sensitive; repair-weld only with 4043/2319 filler, low heat input and preheat, and re-solution treat where properties matter.
Can ZL203 be formed, bent or molded?
Sand and permanent-mould casting only; long freezing range demands generous risers, chills and directional solidification to avoid hot tears and shrinkage porosity — not suitable for pressure-tight castings.
ZL203 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 |
|---|---|---|
| Cuprincipal strengthening element | 4 – 5 | 4.5 |
| Siimpurity limit (sand cast); improves fluidity | ≤ 1.2 | 0.6 |
| Feimpurity; 1.0 max for permanent-mould in some sources | ≤ 0.8 | |
| Mgimpurity | ≤ 0.05 | |
| Mnimpurity | ≤ 0.1 | |
| Znimpurity | ≤ 0.25 | |
| Niimpurity | ≤ 0.1 | |
| Tigrain refiner residue / impurity | ≤ 0.2 | |
| others (each)total impurities ≤ 2.1 % (sand) / ≤ 1.5 % (permanent mould) | ≤ 0.05 | |
| Al | balance |
What surface finishes work on ZL203?
Anodizing gives grey, non-decorative films because of the copper; prefer chromate/phosphate conversion coating plus primer and paint, or hard anodize where wear resistance dominates.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum ZL203 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does ZL203 cost?
ZL203 is a standard-cost aluminum ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ZL203 — frequently asked
What is ZL203 used for?
ZL203 is typically used for general machinery castings, gear housings and covers, machine tool brackets and bases, fixture and jig bodies, non-pressure instrument housings and heavily machined prototype castings. In short: best-machining cast aluminum; low-cost Al-Cu sand casting; not for pressure-tight parts.
What is the yield strength of ZL203?
ZL203 has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 81% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is ZL203 easy to machine?
Yes — machinability is rated very good (80/100, better than 92% of aluminum grades). Excellent — one of the best-machining cast aluminium alloys; use polished-flute carbide or PCD, high speed, low feed, and flood coolant; T5/T6 gives cleaner surfaces than as-cast.
Can ZL203 be welded?
Not readily — weldability is rated poor (25/100). Poor — Al-Cu is highly hot-crack sensitive; repair-weld only with 4043/2319 filler, low heat input and preheat, and re-solution treat where properties matter.
What surface finishes work on ZL203?
Anodizing gives grey, non-decorative films because of the copper; prefer chromate/phosphate conversion coating plus primer and paint, or hard anodize where wear resistance dominates.
Can ZL203 be formed, bent or molded?
Sand and permanent-mould casting only; long freezing range demands generous risers, chills and directional solidification to avoid hot tears and shrinkage porosity — not suitable for pressure-tight castings.
What is the maximum service temperature of ZL203?
ZL203 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 ZL203-T4 and ZL203-T6?
T4 is the default condition — standard supply condition: best combination of strength and ductility/toughness for general engineering castings. T6: peak-strength condition used mainly on the ANSI 295.0 equivalent when maximum hardness/wear resistance is required. Yield strength is 110 MPa in T4 versus 165 MPa in T6.
How much does ZL203 cost?
ZL203 is a standard-cost aluminum ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (295.0, 208.0 data) — ASM International (1990)
- ASTM B26/B26M — Aluminum-Alloy Sand Castings — ASTM International (2018)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.