Machining Keys

Parallel Keys are the most widely used. They have a square or rectangular cross-section. Square keys are used for smaller shafts and rectangular faced keys are used for shaft diameters over 6.5 in (170 mm) or when the wall thickness of the mating hub is an issue. Set screws often accompany parallel keys to lock the mating parts into place. The keyway is a longitudinal slot in both the shaft and mating part.
 
Parallel Keys are generally used for Automobiles, gearboxes, starters, alternators, fuel injection pumps, oil pumps, water pumps and brake compressors, Two wheelers, Electric motors, alternators and switch gears, Machine tools and all types of pumps Textile machineries, Pharmasitical Machinery, Heavy Duty Machinery, Earth moving Machinery, Automotive Cran etc.

The cross section of the key is either square or rectangular and hence the name. This is the most standardized version of keys currently being used in all applications. The size of the key to be selected based on the shaft size is already been standardized for rectangular keys. The chart is enclosed below as a ready reference.  
 
Rectangular Keys are generally used for Automobiles, gearboxes, starters, alternators, fuel injection pumps, oil pumps, water pumps and brake compressors, Two wheelers,Electric motors, alternators and switch gears, Machine tools and all types of pumps Textile machineries,Pharmasitical Machinery, Heavy Duty Machinery, Earth moving Machinery, Automotive Cran etc.

This article about Shaft Keys describes the types of keys and the design or selection procedures to be adopted.Shafts are indispensable mechanical power transmission elements that are mainly used in for transmitting rotary motion and torque from one point to another point. The various other mechanical elements like gears, cams, sprockets, etc. are mounted on the shaft at the required locations. One of the major mounting methods used for connecting such mechanical elements in place is by keys.
 
Shaft keys are generally used for Automobiles, gearboxes, starters, alternators, fuel injection pumps, oil pumps, water pumps and brake compressors, Two wheelers, Electric motors, alternators and switch gears, Machine tools and all types of pumps Textile machineries, Pharmasitical Machinery, Heavy Duty Machinery, Earth moving Machinery, Automotive Cran etc.

The Woodruff Keys is so called because of its manufacturing method. It consists of a semicircular key seat on the shaft surface which holds the key. The key is in the shape of a section of a circle. This type of key tends to have a lesser shear strength than compared to that of a rectangular or square key.
 
Woodruff keys are semicircular shaped, such that, when installed, leave a protruding tab. The keyway in the shaft is a semi-circular pocket, the mating part, a longitudinal slot. They are used to improve the concentricity of the shaft and the mating part, which is critical for high speed operation. The main advantage of the Woodruff key is that it eliminates milling a keyway near shaft shoulders, which already have stress concentrations.
 
Woodruff Keys are generally used for Automobiles, gearboxes, starters, alternators, fuel injection pumps, oil pumps, water pumps and brake compressors, Two wheelers, Electric motors, alternators and switch gears, Machine tools and all types of pumps Textile machineries, Pharmaceutical Machinery, Heavy Duty Machinery, Earth moving Machinery, Automotive Cran etc.