These are divided into three basic types PA6, PA66 and PA12
The main benefits of using PA are

1. High mechanical strength, hardness, rigidity & toughness
2. High mechanical damping properties
3. Good fatigue resistance
4. Very high wear resistance
5. Good sliding and emergency running properties
6. Good machining properties
7. Good Electrical Insulating properties
8. Good resistance to high energy radiation (Gamma & X-rays)

The standard stock shapes are manufactured by two methods.
Casting & Extrusion
Casting grades:- These grades are denoted by the suffix ‘G’ and these grades exhibit high mechanical strength, stiffness, heat, impact strength, creep resistance and wear resistance
The commonly used casting grades are:-
PA6G Standard cast Polyamides for components, and equipment that are subject to above conditions.
Colors: natural, black.
PA6 is also available in an oil filled grade called Oilamid which offers superior self-lubricating properties and MoS2 filled grade which has a higher degree of crystallinity.
Applications: Gears, wear pads, bushings, bearings, conveyor plates, pump impellors etc.
PA12G This is a special purpose grade used when higher impact and shock resistance, less water absorption and improved creep resistance is required.
Extrusion Grades Extrusion grades are denoted by the suffix ‘E’, these are produced in smaller thicknesses and diameters and offer superior damping properties to casting grades.
The commonly available grades are:
PA6E This is a standard multipurpose grade and offer a good combination of mechanical stability, impact resistance and damping but much lower wear resistance to casting grades.
Applications: hammer heads, gear wheel etc.
PA66E This is harder than PA6 and is more resistant to wear but has lesser impact resistance.
PA12E Has very low water absorption proportion hence has very good impact behavior and is tough, but is much more costlier than PA6.
Colors: natural and black.