Complete reference chart for aluminium casting alloys — LM0 to LM31 international equivalents across British/Indian, ISO, EN AC, French, German, Italian, American (ASTM/AA), SAE and Japanese (JIS) standards. Includes recommended end uses and full chemical composition per BS 1490:1988. Published by Audhe Industries — ISO 9001:2015 certified aluminium casting manufacturer, Coimbatore, Tamil Nadu, India.
Start with your component's mechanical property requirements — UTS, yield strength, elongation — and your casting method (GDC, sand, PDC). These two factors narrow the alloy choice significantly.
Use the Recommended End Use table to find the LM grade that suits your application category — automotive, marine, structural, piston, etc. The most common choices are LM4, LM6, LM24 and LM25.
Once you have the LM grade, use the International Equivalents table to find the equivalent in your country's standard — ASTM/AA (USA), DIN (Germany), EN AC (Europe), JIS (Japan) or IS (India).
Of the 21 LM grades in this chart, these six account for the vast majority of aluminium casting production worldwide — and are the grades Audhe Industries casts most frequently at our Coimbatore foundry.
Most widely used PDC alloy — excellent fluidity, thin walls, automotive and electrical housings
Most versatile; good castability for pump bodies, valve housings — heat-treatable
High Si, thin wall castings, marine and food equipment — best ductility of all LM grades
High-volume automotive PDC — engine brackets, transmission housings, covers
T6 heat treatment gives 280MPa UTS — structural, hydraulic, aerospace applications
Higher strength than LM6 after heat treatment — low-pressure die casting applications
Reference data sourced from British Standards and Indian Standards for aluminium casting alloys. All grades listed are regularly cast by Audhe Industries at our Coimbatore foundry — contact us to confirm availability and lead time for any specific grade.
LM grades (UK/India) cross-referenced against ISO, EN AC, French, German, Italian UNI, American AA/ASTM, SAE and Japanese JIS designations — per BS 1490:1988
| UK / INDIA | ISO | EN AC- | FRANCE | GERMANY | ITALY UNI | USA AA/ASTM | USA SAE | JAPAN |
|---|---|---|---|---|---|---|---|---|
| LM 0 | Al 99.5 | A5 | 3950 | 150 | ||||
| LM 2 | Al-Si10Cu2Fe | 46 100 | A-S9U3-Y4 | 5076 | 384 | 383 | ADC 12 | |
| LM 4 | Al-Si5Cu3 | 45 200 | A-S5U3 | G-AlSi6Cu4 (225) | 3052 | 319 | 326 | AC 2A |
| LM 5 | Al-Mg5Sil AlMg6 | 51 300 | AG6 | G-AlMg5 (244) | 3058 | 514 | 320 | AC 7A |
| LM 6 | Al-Si12 Al-Si12Fe | 44 100 | AS 13 | G-AlSi12 (230) | 4514 | A413 | AC 3A | |
| LM 9 | Al-Si10Mg | 43 100 | A-S10G | G-AlSi10Mg (233) | 3049 | A360 | 309 | AC 4A |
| LM 12 | Al-Cu10Si2Mg | A-U10G | 3041 | 222 | 34 | |||
| LM 13 | Al-Si12Cu Al-Si12CuFe | 48 000 | A-S12UN | 3050 | 336 | 321 | AC 8A | |
| LM 16 | Al-Si5Cu1Mg | 45 300 | A-S4UG | 3600 | 355 | 322 | AC 4D | |
| LM 20 | Al-Si12Cu Al-Si12CuFe | 47 000 | A-S12-Y4 | G-AlSi12(Cu) (231) | 5079 | A413 | 305 | |
| LM 21 | Al-Si6Cu4 | 45 000 | A-S5U2 | G-AlSi6Cu4 (225) | 7369/4 | 308 | 326 | AC 2A |
| LM 22 | Al-Si5Cu3 | 45 400 | A-S5U | G-AlSi6Cu4 (225) | 3052 | 319 | 326 | AC 2A |
| LM 24 | Al-Si8Cu3Fe | 46 500 | A-S9U3A-Y4 | G-AlSi8Cu3 (226) | 5075 3601 | A380 | 306 | AC 4B ADC10 |
| LM 25 | Al-Si7Mg | 42 000 | A-S7G | G-AlSi7Mg | 3599 | A356 | 323 | AC 4C |
| LM 26 | Al-Si9Cu3Mg- | A-S7U3G | 3050 | 332 | 332 | |||
| LM 27 | Al-Si7Cu2Mn0.5 | 46 600 | 7369 | AC 2B | ||||
| LM 28 | Al-Si19CuMgNi | 6251 | ||||||
| LM 29 | Al-Si23CuMgNi | 6251 | ||||||
| LM 30 | Al-Si17Cu4Mg | 390 | ||||||
| LM 31 | Al-Zn5 | 71 000 | A-Z5G | 3602 | 712 | 310 |
Note: Empty cells indicate no direct equivalent exists in that standard. Always verify alloy suitability with your foundry before specifying — contact Audhe Industries for advice on alloy selection for your application.
Application guide for each LM grade — casting method suitability, industry applications and key properties for component selection
| Grade | Recommended Application & Notes |
|---|---|
| LM 0 | Alloy suitable for Sand Casting, components for Electrical, Chemical and Food Processing Industries. |
| LM 2 | One of the two most widely used alloys for all types of die-castings. |
| LM 4 | The most versatile of the alloys, has very good casting characteristics and is used for a very wide range of applications. Strength and Hardness can be greatly increased by Heat Treatment. |
| LM 5 | Suitable for Sand and Chill Castings requiring maximum corrosion resistance i.e. castings of marine application. |
| LM 6 | Suitable for large, intricate and thin walled castings in all types of moulds, also used where corrosion resistance or ductility is required. |
| LM 9 | Used for applications especially low pressure die casting requiring the characteristics of LM 6 with higher tensile strength after heat treatment. |
| LM 12 | Mainly used for sand and chill castings requiring high strength and shock resistance. Requires special foundry techniques and heat treatment. |
| LM 13 | Mainly used for piston and applications where thermal stresses are more. This alloy can withstand higher temperatures and loads. It has good wear resistance properties and machinability. Requires heat treatment. |
| LM 16 | Suitable where high mechanical properties are desired in fairly intricate sand and chill castings. Requires heat treatment. |
| LM 20 | Mainly used for pressure die casting. Similar to LM 6 but with better machinability and hardness. |
| LM 21 | Generally similar to LM 4M in character and application but better machinability and proof strength. |
| LM 22 | Used for chill castings requiring good foundry characteristics and good ductility. Requires heat treatment. |
| LM 24 | Suitable for large, intricate and thin walled castings in all types of moulds, also used where corrosion resistance or ductility is required. |
| LM 25 | Suitable where good corrosion resistance combined with thermal properties are required. Strength is attained by heat treatment. |
| LM 26 | Mainly used for pistons as alternate to LM 13. |
| LM 27 | A versatile sand and chill cast alloy introduced as an alternative to LM 4 and LM 21. |
| LM 28 | Piston alloy with lower coefficient of thermal expansion than LM 13. This alloy use requires special foundry technique. |
| LM 29 | Same characteristics as LM 28 but with still lower coefficient of thermal expansion than LM 28. |
| LM 30 | For unlined die cast cylinder blocks with low expansion and excellent wear resistance. |
| LM 31 | Zinc-based aluminium alloy — used where high strength and good corrosion resistance are required. |
Per BS 1490:1988 Standard — maximum percentage values for each element unless shown as a range. All values are weight percent (%).
| Alloy | Cu | Mg | Si | Fe | Mn | Ni | Zn | Pb | Sn | Ti | Additional Elements | Others |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| LM 0 | 0.03 | 0.03 | 0.3 | 0.4 | 0.03 | 0.03 | 0.07 | 0.03 | 0.03 | — | Al 99.50 min | — |
| LM 2 | 0.7–2.5 | 0.3 | 9.0–11.5 | 1 | 0.5 | 0.5 | 2 | 0.3 | 0.2 | 0.2 | — | 0.5 |
| LM 4 | 2.0–4.0 | 0.2 | 4.0–6.0 | 0.8 | 0.2–0.6 | 0.3 | 0.5 | 0.1 | 0.1 | 0.2 | — | 0.2 |
| LM 5 | 0.1 | 3.0–6.0 | 0.3 | 0.6 | 0.3–0.7 | 0.1 | 0.1 | 0.05 | 0.05 | 0.2 | — | 0.2 |
| LM 6 | 0.1 | 0.1 | 10.0–13.0 | 0.6 | 0.5 | 0.1 | 0.1 | 0.1 | 0.05 | 0.2 | — | 0.2 |
| LM 9 | 0.2 | 0.2–0.6 | 10.0–13.0 | 0.6 | 0.3–0.7 | 0.1 | 0.1 | 0.1 | 0.05 | 0.2 | — | — |
| LM 12 | 9.0–11.0 | 0.2–0.4 | 2.5 | 1 | 0.6 | 0.5 | 0.8 | 0.1 | 0.1 | 0.2 | — | 0.2 |
| LM 13 | 0.7–1.5 | 0.8–1.5 | 10.5–13.0 | 1 | 0.5 | 1.5 | 0.5 | 0.1 | 0.1 | 0.2 | — | — |
| LM 16 | 1.0–1.5 | 0.4–0.6 | 4.5–5.5 | 0.6 | 0.5 | 0.25 | 0.1 | 0.1 | 0.05 | 0.2 | — | — |
| LM 20 | 0.4 | 0.2 | 10.0–13.0 | 1 | 0.5 | 0.1 | 0.2 | 0.1 | 0.1 | 0.2 | — | — |
| LM 21 | 3.0–5.0 | 0.1–0.3 | 5.0–7.0 | 1 | 0.2–0.6 | 0.3 | 2 | 0.2 | 0.1 | 0.2 | — | — |
| LM 22 | 2.8–3.8 | 0.05 | 4.0–6.0 | 0.6 | 0.2–0.6 | 0.15 | 0.15 | 0.1 | 0.05 | 0.2 | — | — |
| LM 24 | 3.0–4.0 | 0.3 | 7.5–9.5 | 1.3 | 0.5 | 0.5 | 3 | 0.3 | 0.2 | 0.2 | — | — |
| LM 25 | 0.2 | 0.2–0.6 | 6.5–7.5 | 0.5 | 0.3 | 0.1 | 0.1 | 0.1 | 0.05 | 0.2 | — | — |
| LM 26 | 2.0–4.0 | 0.5–1.5 | 8.5–10.5 | 1.2 | 0.5 | 1 | 1 | 0.2 | 0.1 | 0.2 | — | — |
| LM 27 | 1.5–2.5 | 0.35 | 6.0–8.0 | 0.8 | 0.2–0.6 | 0.3 | 1 | 0.2 | 0.1 | 0.2 | — | — |
| LM 28 | 1.3–1.8 | 0.8–1.5 | 17.0–20.0 | 0.7 | 0.6 | 0.8–1.5 | 0.2 | 0.1 | 0.1 | 0.2 | — | — |
| LM 29 | 0.8–1.3 | 0.8–1.3 | 22.0–25.0 | 0.7 | 0.6 | 0.8–1.3 | 0.2 | 0.1 | 0.1 | 0.2 | — | — |
| LM 30 | 4.0–5.0 | 0.4–0.7 | 16.0–18.0 | 1.1 | 0.3 | 0.1 | 0.2 | 0.1 | 0.1 | 0.2 | — | — |
| LM 31 | 0.1 | 0.5–0.75 | 0.25 | 0.5 | 0.1 | 0.1 | 4.8–5.7 | 0.05 | 0.05 | 0.2 | — | — |
Source: BS 1490:1988 — Specification for aluminium and aluminium alloy ingots and castings for general engineering purposes. Values shown are maximum limits (%) unless shown as a range. Consult Audhe Industries for OES-verified material certificates on production castings.
If you're looking for a reliable aluminium casting supplier in India that delivers high-quality, precision-engineered components, Audhe Industries is here to help. Whether you need GDC parts in LM25, pressure die cast parts in LM24, or custom aluminium castings in any LM grade, we are ready to fulfill your requirements.
Now that you have the alloy chart, send us your drawing. Our foundry engineers will confirm the optimal LM grade and casting method for your component — gravity die, sand or pressure die — and provide a competitive quote within 24 hours. ISO 9001:2015 certified, OES verified, COC with every batch.