Material selection decision
Aluminum is a family of alloys and product forms, not one interchangeable material. A machined billet, bent sheet component and finished housing can require different grades, tempers, stock, tolerances and surface controls. MakeNexa reviews the part and program across its supplier network, while exact alloy, availability, properties, price, timing and evidence remain specific to the RFQ.
Selection criteria
Begin with function: load path, stiffness, mass, temperature, corrosion environment, conductivity, joining, appearance and service life. Separate required properties from a familiar grade name. Aluminum 6061 is widely considered for general machined parts, while 7075 can support different strength-driven decisions, but neither is universally preferred. Sheet alloys and tempers may be more suitable where forming, welding or thin-wall fabrication controls the route. The exact product form and temper affect properties and manufacturability.
Provide the controlled geometry, grade or required property range, temper, quantity, final finish, critical interfaces and material-record needs. Identify whether alternate alloys or stock forms may be proposed and what must be revalidated if they change. MakeNexa can compare feasible network routes, but page-level descriptions do not establish achieved strength, corrosion behavior, weld quality, anodized appearance or compliance for an individual component.
Where the material fits
The material decision becomes useful only when the available starting form and final process are considered together.
Bar, plate and near-net stock can support milled and turned parts when allowance, grain direction, flatness and material condition fit the geometry. Large removal, thin walls and residual stress may change the setup and stabilization plan.
Sheet grade, temper, thickness, bend direction, radius and joining route control fabrication. A grade chosen for machining should not be assumed to form or weld like a purpose-selected sheet product.
State the load, stiffness, fatigue, temperature and weight objective that drives the selection. Use exact engineering requirements and approved data rather than treating one strength-to-weight description as sufficient for every design.
Anodizing, conversion coating, blasting, painting and local masking can change dimensions, conductivity, color and cosmetic appearance. Define the final-state fits and protected surfaces before machining allowances are released.
Material tradeoffs
Two aluminum grades can look similar in raw form while creating different supply, process and acceptance questions.
Alloy alone may not define the delivered mechanical condition. Provide temper and product form where required, and identify whether heat treatment, stress relief or later forming changes the accepted state.
Asymmetric removal, thin walls, large plate and residual stress can release movement during machining. Mark flatness, datum and final-state requirements so stock selection, setup sequence and inspection state can be reviewed.
Welding can change local condition, distortion, appearance and downstream finish. Define joint, filler, heat-treatment context, final dimensions and inspection rather than applying base-material properties to the complete welded assembly.
Surface preparation, alloy, temper, geometry, welds, coating route and viewing conditions affect the visible result. Mark cosmetic zones and use a reviewed reference when appearance matters.
Grade and route choices
Use the family page to narrow the problem, then move to the specific grade and manufacturing route that controls the RFQ.
Review Aluminum 6061 when the program needs a broadly sourced general-purpose machined or fabricated alloy, while still confirming temper, product form, strength, finish, welding and evidence for the part.
Review Aluminum 7075 when a higher-strength alloy family may fit the design. Evaluate corrosion strategy, joining, stock, machining, heat-treatment condition and regulated-use evidence rather than selecting it from strength alone.
For bending, deep forming, welding, conductivity or appearance, a different sheet or specialty alloy may fit better. State controlling properties and allow named alternatives only with their route and validation consequences returned.
Material comparison
Typical published values for one representative alloy and temper per series. Actual values vary with grade, temper, product form and the supplier's material certification, and the project requirement is confirmed on the reviewed quote rather than from this table.
| Series and representative alloy | Typical published strength | What the series is chosen for |
|---|---|---|
| 1xxx — 1100-H14, commercially pure | About 117 MPa / 17 ksi yield, 124 MPa / 18 ksi ultimate | Electrical and thermal conductivity near 59% IACS, and forming — not structure |
| 2xxx — 2024-T351, copper | 324 MPa / 47 ksi yield, 469 MPa / 68 ksi ultimate | Fatigue and damage tolerance, at the cost of corrosion resistance and weldability |
| 3xxx — 3003-H14, manganese | About 145 MPa / 21 ksi yield, 152 MPa / 22 ksi ultimate | Formed sheet, tube and general fabrication where strength is secondary |
| 5xxx — 5052-H32, magnesium | 193 MPa / 28 ksi yield, 228 MPa / 33 ksi ultimate | Bending at roughly 1× material thickness and the best salt-water resistance of the family |
| 6xxx — 6061-T6, magnesium-silicon | 276 MPa / 40 ksi yield, 310 MPa / 45 ksi ultimate | The general-purpose machined and welded structural default |
| 7xxx — 7075-T6, zinc | 503 MPa / 73 ksi yield, 572 MPa / 83 ksi ultimate | Strength-led machined parts, with no fusion welding and stress-corrosion risk in T6 |
| Stiffness across all six series | 68 to 73 GPa modulus — a spread of under 8% | Alloy choice moves strength by more than a factor of four and stiffness by almost nothing: a deflection problem is solved by section, not by grade |
| Density across all six series | 2.66 to 2.85 g/cm³ | Mass is set by the section the strength requires, not by the alloy name |
| Thermal expansion | About 23 to 24 µm per metre per °C across the family, roughly double steel | A 200 mm feature moves about 0.05 mm across a 10 °C change — state the measurement temperature on tight fits |
| Common specifications | ASTM B209 for sheet and plate, ASTM B221 for extrusion, ASTM B211 for bar | Which specification the mill certificate must reference |
Material RFQ inputs
Provide enough functional and material context to compare a named grade with any permitted alternative honestly.
Complete packages move faster: revision-matched CAD, critical dimensions, quantity and material notes are enough to open engineering review across the network.
Get a QuoteSubmit the controlled model, drawing, revision and application environment
State aluminum alloy, temper and product form or the controlling property requirements
Identify load, stiffness, temperature, corrosion, weight and conductivity constraints that affect selection
Define machining, forming, welding, heat treatment and distortion-sensitive final geometry
Specify anodizing or other finish, cosmetic zones, masks, electrical contacts and final-state dimensions
List quantities, material records, inspection, packaging and approved-alternative rules
Questions before routing
These answers prepare the request; the reviewed quote controls project-specific commitments.
6061-T6 is the usual default: 276 MPa / 40 ksi yield, good corrosion resistance, clean anodizing and wide stock availability in bar, plate and extrusion. 7075-T6 is chosen when strength governs at about 503 MPa / 73 ksi, and it actually breaks chips better at roughly 150 HB against 95 HB. 2011 is the choice for high-volume turned work because its chips break short. There is no single best grade — the answer follows the load case, the finish and the quantity.
7075-T6 publishes about 503 MPa / 73 ksi yield against 276 MPa / 40 ksi for 6061-T6, so it wins on strength by a wide margin. But stiffness is nearly identical — 71.7 against 68.9 GPa — so a deflection-limited part gains nothing, and 7075 is denser at 2.81 against 2.70 g/cm³, commonly 1.5 to 2 times the cost, not fusion weldable, and stress-corrosion susceptible in T6. Start from 6061 and move only when the load case forces it.
Barely. Modulus across the common aluminium alloys runs from about 68 to 73 GPa — under 8% spread — while yield strength ranges from roughly 117 MPa in 1100-H14 to 503 MPa in 7075-T6. If a bracket deflects too much, upgrading the alloy will not fix it; adding section depth, a rib or a gusset will. Alloy choice answers strength, fatigue, corrosion, weldability and finish, not stiffness.
Sometimes, but the grade that machines well often bends badly. 6061-T6 machines cleanly and takes a 90° bend at roughly 2 to 3× material thickness; 5052-H32 bends at about 1× and resists salt water better, but publishes lower strength at 193 MPa / 28 ksi. Mixed assemblies commonly use 6061 for machined components and 5052 for folded sheet, and state that split in the RFQ rather than forcing one grade across both.
No, and the alloy is usually the reason two parts do not match. 6063 gives the cleanest, most consistent film, 6061 anodizes predictably, and the copper- and zinc-bearing 2xxx and 7xxx alloys come out duller and harder to hold consistent across lots. Free-machining 2011 anodizes to a blotchy grey. Type II sulphuric typically adds 5 to 25 µm growing about half outward. Where colour is contractual, supply a controlled reference and keep visible parts on one alloy.
Next step
Send the material requirement with geometry and use context. MakeNexa routes capable suppliers from a global network covering competitor-class process categories, then returns a prepared quote or focused clarification for your revision.
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