Three facts that decide this page
- 5052 is the usual choice for formed covers and brackets because it forms better than 6061 at the same thickness, while 6061 is specified where strength or machinability matters more than formability.
- Three CLOOS robotic MIG cells plus more than 30 manual stations cover repeat assemblies and one-off frames; the robot only pays back when the fixture holds the joint in the same place every cycle.
- The oxide layer melts at a much higher temperature than the metal underneath, so it must be removed mechanically before welding. Aluminium conducts heat away quickly, which means more heat input and more distortion on thin sheet. 6061 is heat-treatable and loses strength in the heat-affected zone unless the assembly is re-aged.
What changes when you weld aluminium
The oxide layer melts at a much higher temperature than the metal underneath, so it must be removed mechanically before welding. Aluminium conducts heat away quickly, which means more heat input and more distortion on thin sheet. 6061 is heat-treatable and loses strength in the heat-affected zone unless the assembly is re-aged.
The commercial consequence is that aluminium is priced on its own material line, not blended into a steel rate. Material grade, thickness, tolerance and finish are quoted separately from conversion, so a change of specification is visible in the price.
Tolerance, edge and finish
Ganesh quotes to the drawing first and to ISO 2768 general tolerances where the drawing is silent. For aluminium welding, the practical starting points are in the table below. They are starting points, not a guarantee: the part geometry, thickness and fixturing decide what can actually be held, and the quotation states the tolerance offered.
How Ganesh runs this route
Welding fixtures are designed and built in the Ganesh tool room, which is why assembly geometry is controlled by steel, not by a welder's eye. Aluminium needs a dedicated pretreatment; a phosphate line built for steel will not give the same adhesion, and chromate-free conversion is the practical route for a mixed-material shop. The route is quoted as one sequence so the customer does not have to coordinate a cutter, a former, a welder and a coater.
When welding is the wrong route for aluminium
Welding is often the wrong answer for thin aluminium panels where a folded and riveted or bonded joint would hold flatter and keep the temper.
A manufacturability review before quotation is the cheapest place to find this out. Send the drawing, material, finish and annual quantity and the review comes back in writing.
Typical parts
- Canopy panels
- Enclosure frames
- Battery boxes
- Equipment covers
Decision rule: when to choose welding
Weld when the assembly cannot be formed as one part or must be shipped knocked down. Robotic MIG pays back on repeat assemblies where the fixture holds the joint in the same place every cycle; below a few hundred identical assemblies a year, a fixture and manual MIG are usually more economic. Do not weld where the customer needs a flat, unmarked panel or where the assembly must be disassembled for service. For aluminium the practical constraint is the oxide layer and the alloy temper: pretreatment, bend radius and weld procedure all change relative to steel, and the drawing needs to name the alloy, not just the word aluminium. Aluminium is where the alloy decision matters as much as the process decision: a part specified in 6061 T6 that really needs 5052 will be quoted twice and made badly once.
What to put on the drawing
State the weld symbol or size, whether welds are structural or sealing, the finish requirement on the weld (dressed or as-welded), and the dimensional tolerance on the assembled frame rather than on the individual parts. Say whether the assembly is coated after welding, because that changes the access and the masking plan.
Quality evidence and inspection
Inspection covers weld size and length, visual defects, distortion against the assembly drawing and, where specified, penetration or leak testing. Fixtures are maintained in the tool room. Weld and dimensional records are kept with the batch, and material is traceable to mill certificates.
What drives the cost
Cost splits into fixture amortisation, fit-up, weld time, cleaning and inspection. Fit-up is usually the largest labour element: a part that locates itself in the fixture takes a fraction of the time of one that has to be measured and clamped. Distortion correction, if it is needed, is pure rework cost. On aluminium, material is quoted as its own line at the prevailing rate for the grade and thickness, so a change of specification is visible rather than hidden in a blended rate.
| Specification | aluminium welding | Ganesh limit or note |
|---|---|---|
| Grades | 1050, 5052 and 6061 to ASTM B209 / IS 737 | Grade per drawing |
| Thickness | 0.8–6 mm sheet; cut to 10 mm plate | Robotic MIG, manual MIG/MAG, spot, SPM |
| Tensile / property | 110–310 MPa depending on alloy and temper | 2.70 g/cm³ density |
| Alloy and temper | 1050 H14, 5052 H32, 6061 T6 | 5052 for forming, 6061 for strength |
| Bend radius | 0.8–1.5 × thickness typical | Tight radii crack on 6061 T6 |
| Laser cutting | Fast, high reflectivity | Clean nozzle and correct pierce height |
| Welding | Robotic MIG, manual MIG/MAG, spot, SPM | 3 CLOOS cells, 30+ stations |
| Tolerance basis | ISO 2768-m unless drawing states otherwise | Critical features inspected |
| Finish | Etch or conversion pretreatment, then powder coat where specified | Specified per part |
Sources and review
- ASTM B209 — Aluminium and aluminium-alloy sheet and plate · reviewed 2026-11-03
- IS 737 — Wrought aluminium and aluminium alloy sheet and strip · reviewed 2026-11-03
- ISO 2768-1 — General tolerances · reviewed 2026-11-03
- AWS D1.2 structural welding of aluminium · reviewed 2026-11-03
Combines Ganesh machine limits (Robotic MIG, manual MIG/MAG, spot, SPM) with aluminium grade and property data. The "what changes" section is written for this material–process pair and is not reused on another page.
Send the drawing and we will check the route
Material, thickness, tolerance, finish and annual quantity are enough for a manufacturability review. Tooling is quoted separately from the piece price.
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