Pistons available in :
Normal/Alfin (Ring Carrier) Type / Shims Type, Tin Plated, Black Graphite Coated, Top Anodized Aluminium Pistons are made from gravity die casting. Molten Aluminium alloy is poured into a table top steel die which has runner and riser to keep out the impurities from the main casted piston. A variety of alloys are used for the pistons depending upon the application and use of the piston. Silicon, Copper, Nickel and Magnesium are mainly part of the alloy. The Piston after proof machining has to be heat treated in furnace. The piston is then machined to accurate size on the principal of center to center with reference to the central axis of the piston. Most pistons are cam turned to achieve ovality.The alloy of the Piston must be wear resistant, have good thermal conductivity, a good design to keep the piston from over heating.
Piston Rings :
LCast Iron Rings are individually casted and cam turned to accurate size. The thickness is grinded on double disc grinder. They are all wear resistant and ensure maximum sealing. SG Iron Rings are centrifugally barrel casted and heat treated. Top & Oil Chrome Rings are chrome plated 250 microns. They are all barrel horned/outside grinded to have super sealing in the Cylinder. Oil Rings with profile grinded are also available.The cast iron alloy has Nickel, Chromium, Molybdenum etc. making them wear resistant and not to loose tension at high temperature.
Piston Pins / Gudgeon Pins / Wrist Pins :
In an important part of the Piston Assy. Most piston accidents take place because of breaking of the pins. The pins are normally made from 16 MnCr3 or 20 MnCr5. Newer alloys also are used for the pin depending on application. They are case hardened to around 60 HRC and depth of about 1mm only. The outside crust should be hardened in induction furnace. If not pin are likely to break in the high speed working of the engine. Pins are available in “Free Floating”, “Thumb Push” or “Tight Fit” category.