NAMES AND DEFINITIONS
Vocabulary used in describing abrasive tools
Abrasive materials - basic information
Abrasive material - material in the form of grains of a certain size and shape, having the properties of cutting blades.
Abrasive grain number - a numerical discriminator that characterizes the size range of grains (also called granularity or grit).
Grain and micrograin size - the characteristic dimension of the abrasive grain (micrograin) in [mm] or [μm].
According to the criterion of origin, abrasives are divided into:
• natural (e.g., corundum, diamond)
• artificial, obtained by electrothermal and physicochemical processes (e.g., electrocorundum, silicon carbide, synthetic diamond, CBN)
According to the criterion of hardness, abrasives are divided into:
• hard (electrocorundum, silicon carbides, etc.), often referred to as conventional abrasives
• superhard (diamond, CBN).
Abrasive tools - basic information
Abrasive tools are divided into:
• bonded
• coated
BONDED ABRASIVE TOOLS
Bonded abrasive tools are made of abrasive compound, which is a mixture of abrasive grain and bond. The pores between the abrasive grain and the bond also have a significant impact on the grinding process. Grinding wheels, abrasive segments and sharpening stones can be distinguished among bonded abrasive tools.
In this group, ANDRE offers both conventional and superhard tools:
• ceramic bonded abrasive tools
• resin bonded abrasive tools
STRUCTURE OF BONDED ABRASIVE TOOLS
Abrasive material
Structure (for bonded abrasive tools only) - a number indicating the percentage of abrasive material in the total volume of the abrasive tool.
Concentration (for super-hard tools only) - an amount of super-hard grain (diamond or CBN) per 1cm3 of the working layer of the grinding wheel.
Bond - material that binds the abrasive grains. e.g.:
• ceramic
• resin (organic)
• galvanic.
The hardness of the bonded abrasive tool - the measure of the force required to pull the grain out of the surrounding bond. Marked on a letter scale from E to Z.
SEMI-FLEXIBLE ABRASIVE TOOLS (COATED)
In coated abrasive tools, the abrasive layer is fixed on a substrate, e.g.: made of paper, cloth, fiber by means of adhesives.
Backing - the base in case of coated abrasive tools, made of paper, cloth, fiber to which the grain is attached using a bond.
Coated abrasive tools in ANDRE's offer:
• flap wheels
• semi-flexible grinding discs with profiled abrasive coating
• CBS discs
• mounted flap wheels
• fiber discs
• non-wovens.