There are typically six types of oilstones classified by material: Green Silicon Carbide, White Corundum, Brown Corundum, Boron Carbide, Ruby (also known as Sintered Corundum), and Natural Jade.

Overview
Oil stone
Oilstone is a type of natural mineral that has undergone sintering.
Classification
Whetstone Sintered Corundum (Ruby) Oil Stone: It is a type of microcrystalline corundum product that is sintered using high temperatures. The structure is compact and fine, with high hardness and strength.
The product comes in a rosy red color and is available in three types: small grinding wheel-type oil stone, standard type oil stone, and grinding head-type oil stone.
When grinding a workpiece, it maintains a sharp edge and stable geometry for an extended period of time.
It is suitable for forming and grinding in the instrument industry, precision parts, micro tools, tools, precision grinding tools, and more. The precision of the surface roughness can reach 0.05μm.
Product Specifications:
- Small grinding wheel-type flat grinding wheel with a diameter less than 100mm
- Standard geometry of various sizes of oil stone within 2005025mm
- Diameter of grinding head-type oil stone with various shapes within 25mm
- The size of the oil stone is 400#-1200#.
Industrial Applications:
Diamond Fiber Whetstone: This product was introduced using advanced foreign technology in the mid-1990s. It has good elasticity, cutting force, and wear resistance, making it an ideal abrasive tool for mold making, tool repair, bending of various workpieces, and holes that cannot be achieved by ordinary abrasives. It is more cost-effective compared to foreign imports, as its price is only one-third of the latter. Its specifications are 1002-100.5-1.2, and its granularity is 320#-1200#.
Ordinary Oilstone: It is widely used in machinery manufacturing, mold manufacturing, instrumentation, and other related fields.
Super Fine Grinding Stone: The super fine grinding stone, also known as strong grinding oilstone, is widely used in machinery manufacturing, mold manufacturing, instrumentation, and other related fields. Its work efficiency is twice that of an ordinary oilstone.
Ruby Oilstone: Ruby oilstone is a type of corundum microcrystal made of aluminum oxide powder that is sintered at high temperature. The structure is compact and fine, with high hardness and strength. Unlike other oilstones, it does not have varying hardness grades, particle sizes, and strength ranges due to its sintered nature. However, it has a dense structure and a pore structure, resulting in its characteristic rosy red color.
Boron Carbide: Boron Carbide is a hard black shiny crystal, with a hardness lower than industrial diamonds but higher than silicon carbide. Its whetstone size ranges between 400 and 1000, with smaller particle sizes resulting in coarser grain sizes and more grinding for semi-finished tools. Its strong hardness makes it highly wear-resistant and resistant to scratching.
Grinding Method
The particle size of diamond paste ranges from W40 to W0.5.
W40 is the coarsest and provides aggressive grinding.
W0.5 is the finest and is primarily used for polishing. It does not cause annealing and can also be used to sharpen hard knives.
Instructions:
Applying coarse W40 paste to the boron carbide whetstone can increase grinding speed and prevent annealing.
After removing the coarse abrasive paste from the knife, use W0.5 abrasive paste and apply it to a ruby or natural jade stone for polishing, which will produce a mirror-like finish.
The oilstones made of green silicon carbide, white corundum, and brown corundum are not hard enough and have a slightly thick particle size, making them ideal for grinding knives, and they do not cause annealing during polishing or grinding.
The particle size greater than 1000 does not make a significant difference, and it mainly depends on the type of abrasive paste used.
W1.5 paste should be applied to a 1000-mesh ruby stone, which will result in the same grinding effect as a 2500-grit whetstone.