ABRASIVE PRODUCTS

CUTTING AND GRINDING DISCS

Abrasive discs are normally made of aluminium oxide and silicon carbide.

ALUMINIUM OXIDE
Universally indicated with “A”, it is a chemical compound of aluminium and oxygen and a rock-forming material. For its hardness, it can scratch almost every other material, that’s why it is mostly used for steel applications.
REGULAR A It is the most common aluminium oxide abrasive. It is highly resistant and strong, ideal for heavy-duty work such as snagging steel castings, grinding of welding seams, iron and steel cutting. Its crystal structure and fracture characteristics make it suitable for grindings operations of high precision and of big stock removal. It is also used for tools sharpening.
WHITE “A” It is particularly suited for grinding all kinds of tool steels. It has a friable structure and it is used for applications where high precision is required, such as for sharpening high-speed steels and cast alloy tools and cutters, as well as for cylindrical, surface and internal grinding of tools, dies and gages.
SILICON CARBIDE
Universally indicated with “C”. It is better suited for grinding very hard and dense materials like cemented carbides and ceramics, most non-ferrous metals and non-metallic materials such as glass, rubber and stone, as well as cast iron.

WHAT TO CHOOSE

As a rule, large surfaces require the use of coarse grits and abrasives of medium-soft hardness. Vice versa, small surfaces require the use of fine grits and abrasives of higher hardness. Three things are important:

  1. Type of abrasive
  2. Grit dimensions
  3. Disc hardness
TYPE OF ABRASIVE
Characteristics of the material to grind. Abrasive to use.
Steel in general, other ferrous materials, hard bronze, cast iron (it depends on the type and the application). Aluminium oxide in its different types.
Metallic carbides, cast iron (it depends on the type and the application), brass and soft bronze, copper, aluminiun and its alloys, stainless steel, special alloys, non metallic materials. Silicon carbide in its different types.
GRIT DIMENSIONS
Soft and non-treated materialas are easily grinded with coarse grit discs, while hard, fragile and treated materials require the use of a disc of a finer grit. As the penetration depth is limited, better results are obtained removing lots of small shavings.
DISC HARDNESS
As a rule, hard and treated materials require the use of softer grits. As these materials resist to the abrasive grains penetration, they get easily blunted. If the disc is soft, when the grains contact the material, they start to cut and grind the material away. As the grains grind, they fracture to form new cutting points extending the life of the abrasive. Soft and non-treated materials, vice versa, can be operated with harder discs. When a disc is too soft, it is too aggressive and sharp, so you cannot have a good finishing. When a disc is too hard, however, it tends to burn the material and to produce vibrated and veined surfaces.

TECHNICAL DATA ABOUT CUTTING AND GRINDING DISCS

Technical data about cutting and grinding discs

TECHNICAL SPECIFICATIONS

Abrasive
A Aluminium oxide
Z Zirconium
C Silicon carbide
Hardness
N - O - P Soft
Q - R - S Medium
T - U - V Hard
Bond
B Bakelite / resin
BF Bakelite+fibre glass

SAFETY GUIDE

  • Do not exceed the maximum operating speed indicated on the disc.
  • Do not use cutting discs for deburring.
  • Examine the disc carefully before use, do not mount if there are crack evidences.
  • Follow the instructions provided by the disc and the machine manufacturers.
  • Do not use discs for fixed machines on portable machines.