Quality classes for surfaces
The grades are divided into four levels and described as follows:
Grade 1 – These are surfaces that are free of electrode impressions without rework. Annealing is permissible. Feature: After spray painting without previous filling and sanding, the welds must not be visible to the naked eye (only accessible from one side).
Grade 2 – This category includes surfaces where spot weld marks (electrode indentations, annular bead formations, unevenness due to heat loss, etc.) do not exceed 10% of the respective sheet thickness. Feature: After equalisation (straightening, grinding, sanding, filling, etc.), the welds after spray painting must not be visible to the naked eye.
Grade 3 – These are surfaces where spot weld marks do not exceed 25% of the respective individual sheet thickness. Within this framework, adherent weld spatter is also permitted, unless the drawing specifies freedom from burrs and spatter.
Grade 4 – The grade includes all surfaces without any special grade requirements.