The 6061-T6 alloy is chosen for parts demanding real strength, stiffness, and clean machining. It holds tolerances well, taps properly, and finishes consistently by anodizing or powder coating. MIG/TIG welding is common; the heat-affected zone softens, which is normal for T6.
Forming is limited in T6: generous internal radii are better, or favor brackets and gussets over deep draws. From 0.040" to 0.500", it serves structural panels, machine guards and bases, precision supports, frames, jigs, vehicle and trailer components, hinges, plates, and cladding parts requiring stiffness.
Alloy Nature
Magnesium-silicon aluminum, heat-treatable. The T6 temper provides high yield strength and good dimensional stability; appreciated for brackets, frames, and machined areas on sheet metal parts.
Primary Uses
Structural sheet metal parts: frames, gussets, mounting plates, hinges, machine bases and guards.
Precision components: enclosure panels with tapped holes, jigs and fixtures, adapter plates and tooling trays cut from sheet.
Transportation and industrial: truck/trailer panels, ramps, steps, racks, robot plates, and equipment sub-frames.
Secondary uses: skins and covers benefiting from clear or colored anodizing (with generous bends), general lids and panels where stiffness is preferred over tight bend radii.
Strengths
Stiffness/weight ratio: substantially superior to 3003/5052 at equal gauge, useful for limiting oil-canning and deflection.
Machinability: clean drilling, tapping, counterboring, and pockets; threads hold well.
Finishes: accepts anodizing (clear or color) with uniform appearance; powder coating adheres well with proper preparation.
Weldability: MIG/TIG without major difficulty; select filler according to finish and service (5356 for strength/anodized color, 4043 to limit cracking). Expect softening in HAZ.
When It's Not Ideal
Tight bends or deep draws: 6061-T6 cracks more easily in sharp forming. Use large internal radii (generally ≥3–5× thickness, more in heavy gauge), bend cross-grain, or redesign. If tight forming is essential, consider 5052-H32, order in a softer temper, or anneal locally keeping in mind that re-heat-treatment adds cost and distortion.
Severe marine environment: corrosion resistance is good, but for long-term salt exposure, 5052 often performs better.
Thickness Suitability (0.040"–0.500")
0.040"–0.080" (≈1.0–2.0 mm): lightweight structural skins, precision covers with machining, small brackets and hinges.
0.090"–0.190" (≈2.3–4.8 mm): robust guards, machine panels, racks, medium-service flanges, plates with tapped holes.
0.250"–0.500" (≈6.4–12.7 mm): large brackets, rigid bases, clamping plates, adapter plates; excellent for countersunk screws and tapped holes.
Fabrication Notes
Cutting: fiber laser, waterjet, and CNC give clean edges; support thin parts to limit vibration.
Forming: polished tooling and generous die nose; make test coupons before committing to tight designs.
Welding: account for strength drop in and near welds; add gussets or increase sections if needed.
Fastening: works with rivets, bolts, threaded inserts, and self-clinching hardware (respect minimum thickness). Manage galvanic couples with steels or copper alloys.
Finish
Anodizing provides hard, corrosion-resistant surface with uniform tint; brushing then clear varnish common for visible faces. For uniform color on an assembly, group parts from same material lot and follow stable preparation.
Common Applications
Lightweight construction, automotive, robotics and automation, stressed components, aerospace structures, electronic enclosures, bicycle frames, and many sub-assemblies where stiffness, clean machining, and beautiful finishes are sought.