Acetal Bevel Gears Injection moulded acetal (tensile strength 80 N/mm2) gears with machined bores from module 1.5 and up. Pressure angle is 20°, angle between axes is 90°. NOTE: To achieve stated ratios select MATCHED pairs of gears. MATCHED gears have consecutive order codes with identical ratios and modules. To achieve 1:1 ratios order TWO of the same gear