Electroless nickel plating is a chemical process done without applying current by using auto catalytic chemical reduction process in higher temperature and it can be plated over a wide variety of metals like Aluminum, Mild steel, Hardened steel, Stainless steel, Copper and Brass. 

   The main feature of electroless nickel plating is that being a chemical diping process, the deposition is absolutely uniform, and the dimension of components can be maintained within a close tolerance of 1 to 2 micron hence no need to carryout machining or grinding operations. Plating can be successfully acheived highly recessed areas such as deep bores, grooves and blind cavities, unlike in any conventional electrochemical process such as hard chrome plating.
Important features of electroless nickel plating :

1. Corrosion resistant
2. Surface hardness (45 to 55 Hrc)
3. Low friction
4. Conductivity
5. Solderability
6. Bright finish
7. Uniform coating 

Major application of electroless nickel plating :

1. Functional engine components,
2. Pistons,
3. Cylinders,
4. Pump spares,
5. Valve components,
6. Moulds and Dies,  
7. Most complicated designed machinery parts.