MIC-6 Cast Tooling Plate vs 6061-T6
MIC-6 cast tooling plate and 6061-T6 solve opposite problems. MIC-6 is a stress-relieved cast aluminum plate engineered for dimensional flatness and stability — ideal for machine bases and jigs — but it's weak (~165 MPa tensile / 110 MPa yield) and brittle (3% elongation). 6061-T6 is a wrought structural alloy, far stronger (~310 MPa tensile / 276 MPa yield) and ductile, but not guaranteed flat. Flatness versus strength defines the choice.
The verdict
Choose MIC-6 cast plate for flat, stable tooling — machine bases, jig plates, and fixtures where guaranteed flatness, low internal stress, and machinability matter more than load-bearing strength. Choose 6061-T6 for structural and load-bearing parts needing real strength (~276 MPa yield vs 110 MPa) and ductility.
Side-by-side data
| Property | MIC-6 Cast Tooling Plate | 6061-T6 |
|---|---|---|
| Category | Aluminum | Aluminum |
| Density (g/cm³) | 2.7 | 2.7 |
| Tensile strength (MPa) | 165 | 310 |
| Yield strength (MPa) | 110 | 276 |
| Elongation (%) | 3 | 12 |
| Hardness | 65 HB | 95 HB |
| Max service temp (°C) | 150 | 170 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 142 | 167 |
| Typically used for | Flat machine bases & jigs | All-round structural & machined parts — the default aluminum |
Which should you choose?
Choose MIC-6 Cast Tooling Plate when…
- Building flat machine bases, jig plates, and fixtures needing tight flatness
- Dimensional stability after machining is critical (low residual stress, won't warp)
- Parts are large, thick plates that must stay flat across the face
- Excellent machinability and fine surface finish are priorities (4.5 index)
- Vacuum chucks, mold bases, and inspection plates where strength is secondary
- You need a cast plate that machines cleanly without distortion
Choose 6061-T6 when…
- Parts carry real structural or mechanical load (~276 MPa yield)
- Ductility and impact tolerance matter (12% elongation vs MIC-6's 3%)
- You need welding, forming, or bending — MIC-6 is brittle cast plate
- Lower cost is important (~2.0 vs MIC-6's ~3.2 index)
- Threaded, fatigue-loaded, or stressed components are required
- Broad availability in plate, bar, sheet, and extrusion is needed
Key differences that matter
- Strength gap is large: 6061-T6 ~310 MPa tensile / 276 MPa yield vs MIC-6 ~165 MPa / 110 MPa — 6061 has ~2.5x the yield
- MIC-6 is cast and stress-relieved for flatness and dimensional stability; 6061 is wrought and not flatness-guaranteed
- Ductility: 6061 12% elongation vs MIC-6 3% — MIC-6 is brittle and unsuitable for impact or bending
- MIC-6 machines slightly better (4.5 vs 4.5 equal) and holds finish well, with minimal warping after stock removal
- MIC-6 is not weldable in practice (cast, porosity); 6061 welds readily with 4043/5356 filler
- Cost: MIC-6 ~3.2 vs 6061 ~2.0 index — you pay a premium for guaranteed flatness
- Both share ~2.7 g/cc density and ~150–170°C max service temperature
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Open the Material SelectorGet a Quote →Frequently asked questions
What is MIC-6 aluminum used for?
MIC-6 is a cast aluminum tooling plate stress-relieved for exceptional flatness and dimensional stability. It's used for machine bases, jig and fixture plates, mold bases, vacuum chucks, and inspection surfaces — applications where staying flat after machining matters far more than strength. It machines cleanly with minimal warping but is weak and brittle.
Is MIC-6 stronger than 6061?
No, 6061-T6 is much stronger. 6061 reaches about 310 MPa tensile and 276 MPa yield, while MIC-6 cast plate is roughly 165 MPa tensile and 110 MPa yield — about 2.5 times less yield strength. MIC-6 trades strength for guaranteed flatness and stability, so it's a tooling plate, not a structural material.
Can you weld MIC-6 tooling plate?
MIC-6 is generally not recommended for welding. As a cast plate with some internal porosity, welds tend to be unreliable, and the heat input defeats the stress-relieved flatness that is the whole point of the material. If you need a weldable flat plate, use wrought 6061 and machine for flatness instead.
Why is MIC-6 more expensive than 6061?
MIC-6 costs more (about 3.2 vs 2.0 on a relative index) because it's a specialty cast-and-stress-relieved tooling plate manufactured to tight flatness and stability tolerances. You're paying for guaranteed dimensional performance, not mechanical strength. For load-bearing parts where flatness isn't critical, 6061 delivers far more strength per dollar.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.