Grinding wheels

Today’s diesel engines are exposed to significant loads due to the high working pressures and demands of modern engines. It is therefore vital that sealing surfaces are ground very accurately to provide a tight seal to secure long term performance and the best possible service intervals.

Chris-Marine® grinding wheels are selected, tested and proven for each type of metal alloy, surface finish and workload. Choosing the right stones for a specific job is the key aspect for achieving superior grinding results.

A grinding wheel is a precision tool with thousands of cutting points. It consists of abrasive grains held in a matrix of bond and separated by pores. The most important factors defining a grinding wheel are described below.

Abrasive type

  • Aluminium oxide (A)
    • Abrasive grains
    • Bond bridges
    • Several types of aluminium oxide.
    • White – brittle, colored – tensile.
    • Used for hardened and high tensile strength materials.
  • Silicon Carbide (C)
    • Harder than aluminium oxide.
    • Dark green – black color.
    • Used for sintered carbide, cast iron and low tensile strength material.
  • CBN – Cubic Boron Nitride (B)
    • Second hardest abrasive.
    • Uses special types of bonding materials. • Used for hardened steel and high tensile strength materials.
  • Diamond (D)
    • Hardest abrasive.
    • Same type of bonding materials as CBN. • Used for sintered carbide.

Bond type

  • Vitrified (V)
    • Porous structure.
    • Wide range of structures.
    • Insensitive to temperature and solvents. • Easy to dress.
    • Used together with all types of abrasives.
  • Resinoid (B)
    • Compact structure.
    • Less rigid than vitrified.
    • Fine finish can be achieved.
    • Difficult to dress.
    • Used together with CBN and Diamond.
  • Metallic (M)
    • Compact structure.
    • Very stable.
    • Can not be dressed.
    • Used together with CBN and Diamond.
  • Electroplated (G)
    • Single layer of abrasive.
    • Can not be dressed.
    • Used together with CBN and Diamond.

Grade (hardness)

Grade is not a measure of the hardness of the abrasive material but of the durability of the wheel. The hardness varies according to the tenacity with which the bond holds the abrasive grains together. Grade is defined by the alphabetic ranging from ”E” to ”Z”.

E = very soft grinding wheel
Z = very hard grinding wheel

Hard grinding wheels

  • Cuts more slowly.
  • Highest wear resistance.
  • Gives a finer surface finish.

Soft grinding wheels

  • Cuts more quickly.
  • Less wear resistance.
  • Gives a slightly coarser surface finish.