A-grade cleanliness

Before procuring the equipment, we were asked to wash metal pressings to remove oil residues. After washing, we verified the cleanliness level of the treated part. This inspection was carried out using special test markers (dyne pens) designed to assess surface tension. Surface tension is measured in mN/m. The values on the pens are indicated in accordance with ISO 8296/DIN 53364 or their relevant parts. For metals, a surface tension of 38 mN/m or higher is generally required as the minimum cleanliness level.