The bevel gear has the shape of a right circular cone and the large portion of the tip is cut off. Two bevel gears are mesh is such a manner that the imaginary vertices of them occupy the single point. This is also the intersection point of the shaft axes. There is a non straight angle created between shafts. This angle could be anything but not 0 and 180 degrees. Those bevel gears which have same number of teeth and the shaft axes is at 90 degree are known as miter gears.
The bevel gear teeth could be in the form of straight cut like the case of spur gears. Besides this, it could be cut in various other shapes. Spiral bevel gears have curved teeth along the length of tooth. They are placed at some angle. This is quite similar to the manner in which teeth of helical gear are placed at an angle.
Zerol bevel gears consist of teeth that are curved along the length. However, angling is not present in them. The use of straight bevel gears is restricted to situations, where speed required is less than 5 m/s and for smaller gears.
In double helical gears the axial thrust difficulty that is found in single helical gears is overcome. They have two teeth sets which are positioned in V shape. The thrust produced is cancelled out. Both the half of gear produce thrust in opposite direction. They possess a complicated shape and manufacture is comparatively tougher.