Aluminium bicycle and e-bike frames are welded from thin-walled 6xxx and 7xxx tubes, mostly TIG by hand, increasingly MIG on robots. MIGAL.CO supplies MA-4043 and MA-5356 – the classic fillers for 6061 and 7005/7020 frames – plus MA-5183 for higher weld strength and the heat-treatable MA-6063 for frames that are solution-treated and aged after welding. TIG rods are available from 1.6 mm, MIG wire from 0.8 mm on 0.5 kg and 2 kg spools up to drums.
Which filler for which frame?
Typical base materials in bicycle construction and the matching MIGAL.CO filler. For other combinations see the material selection table for aluminium alloys.
| Base material | Typical use | Recommended filler | Why |
|---|---|---|---|
| EN AW-6061, 6082 tubes | frames, rear triangles | MA-4043 (ER4043) | AlSi weld metal prevents solidification cracking on thin-walled tubes |
| EN AW-6061, 6082 frames heat-treated after welding | frames aged to T6 | MA-6063 (AlMg0.7SiTiB) | heat-treatable: Rm 250–280 MPa after T6 instead of 150 MPa as welded |
| EN AW-7005, 7020 (AlZnMg) tubes | frames, forks | MA-5356 or MA-5183 | AlMg fillers recommended for AlZnMg base metals |
| anodised frames | visible welds | MA-5356 (ER5356) | nearly colour-matched after anodising; AlSi welds turn dark grey |
| AlSi castings (dropouts, motor mounts) | cast parts of e-bikes | MA-4046 or MA-4047 | Si content matches the cast alloy |
What matters in frame building
- Thin walls: low heat input and small diameters – TIG rods from 1.6 mm, MIG wire from 0.8 mm.
- Heat treatment: many 6061 frames are solution-treated and aged after welding; a heat-treatable filler such as MA-6063 lets the weld regain strength.
- Small and large series: MIG wire on 0.5 kg (S 100) and 2 kg (S 200) spools up to 40 kg spools and drums; TIG rods in 2.5 kg tubes or 5/10 kg boxes.
- Porosity: vacuum-packed wire, clean and dry tubes, removal of the oxide layer – see welding of aluminium.
Frequently asked questions
Which filler metal is used for aluminium bicycle frames?
For 6061 frames ER4043 is common because it prevents solidification cracking; for 7005 frames ER5356 is common. Where the frame is heat-treated to T6 after welding, a heat-treatable filler such as MA-6063 gives a stronger weld.
ER4043 or ER5356 for bike frames?
ER4043 is more crack-resistant on 6xxx tubes; ER5356 gives higher strength (about 250 MPa vs. 120 MPa), suits AlZnMg tubes such as 7005 and stays nearly colour-matched after anodising.
Which TIG rod diameters are available?
MIGAL.CO TIG rods are 1,000 mm long and available in 1.6–5.0 mm, packed in 2.5 kg tubes or 5/10 kg boxes.
Can I test the filler first?
Yes – request a free test spool.