1. Fish scale welding: As the name suggests, it's like fish scales, one by one! The standard for fish scale welding is: the weld bead width is 7-8mm, with 9-11 pieces per inch, clear and full, without pinholes, sand holes, or false welding. The finishing point should be placed at the 5 or 7 o'clock position.
      
2. Flat welding, also known as Italian flat welding, is commonly used for road vehicles with lower strength requirements. The standard width of the flat welding bead is 11-13mm, and the surface should be uniform without pinholes, pores, undercuts, false welding, and other phenomena.

Space Cardan has 27 years of experience in welding electric bicycle frames, a mature welding technology team, and a stable welding invention patent. Over the past 27 years, it has been exported to more than 50 cities worldwide, ensuring the quality and stability of electric bicycle products.