The specialty of a worm gear and worm wheel is that they provide a large speed ratio but with significant sliding. Another feature being of the worm gear is that most of the designs are non reversible.

Worm Gears are suited for

• right angle skew shafts,
• high velocity ratio ,
• higher speeds and loads.

Although worm gears can be standardized for high precision, they have their own limitations. Worm Gears can be at best considered for average precision meshes, but for works of high precision they have to be selected with care. They are probably the apt choice for a combination of high velocity ratio and right angle drive. Excellent lubrication should always be ensured in use of worm gears since high sliding requires ,lubrication at all times.