This test consists of subjecting the coated surface of the coated glass to rubbing with a felt pad in dry conditions. It is the type of pad, the loading on it and number of strokes that may cause surface degradation.
E.3. The metal finger shall be approximately 15 mm to 20 mm in diameter and shall be driven so as to produce a frequency of 60 strokes/min 6 strokes/min alternating forwards and backwards. The stroke length shall be 120 mm 5 mm. The strokes shall be parallel and ensure a constant pressure over the zone to be tested.