183 Section Pitch Tooth Thickness (mm) T2.5 2.5 T5 5 T10 10 T20 20 AT5 5 AT10 10 AT20 20 height (mm) (mm) 0.7 1.3 1.2 2.2 2.5 4.5 5 8 1.2 2.7 2.5 4.5 5 8