Agriculture machinery like tractors or disc mowers always use bevel gears ,some used spiral bevel gears ,some used straight bevel gears ,some used lapping bevel gears and some required high precision grinding bevel gears .However most of the bevel gears used in agriculture machinery was lapped bevel gears ,the accuracy be DIN8 .However we usually used low carton alloy steel ,to do carburizing in order to meet surface and teeth hardness at 58-62HRC in order to improve gear’s life .