Precision grinding applications involve the removal of material from a workpiece whilst adhering to tight tolerances in industries such as aerospace, automotive and toolmaking. Unlike traditional machining methods like milling or turning, grinding is more abrasive, requiring specialised equipment and grinding tools.
Andor precision grinding tools are locally manufactured from the latest and technologically advanced raw materials, specialised bonding systems, and precise manufacturing processes. Several grain types are utilised in the manufacturing process, each possessing its own unique properties for the best results in various applications.
White Aluminium Oxide, as the most commonly used grain, features a 99% pure, fused aluminium oxide abrasive that is highly friable. This friability allows the abrasive grain to fracture and self-sharpen under pressure, with low loading or glazing, ideal for grinding hardened tool and high-speed steels. As it produces a cooler cutting action, thermal impact is reduced, making it especially suited to tool and cutter grinding applications where most machines are used without coolant.
Another abrasive mineral, Pink aluminium oxide, which is created by adding chromium oxide to white aluminium oxide, enhances its strength and toughness without compromising on friability. It is a tougher grain offering self-sharpening properties with a good balance between durability and precision. On applications suited to tool and cutter grinding, where controlled grinding pressure and prolonged use is required, it offers increased longevity, compared to white aluminium oxide.
A premium abrasive that can be used as an additional alternative between pink and white Alumina in terms of toughness, is Ruby aluminium oxide. Characterised by being slightly harder, it offers excellent edge retention and dimensional control with reduced dressing cycles required during grinding, ultimately lowering downtime.
Sintered aluminium Oxide, more commonly known as seeded gel, represents a leap in abrasive technology, these grains are manufactured through a sintering process that results in microcrystalline structures, offering superior toughness and a micro-fracturing ability.
Utilising sintered aluminium oxide in the manufacture of precision grinding wheels, provides exceptional stock removal rates combined with a cool grinding action that minimises workpiece burn, and significantly increases longevity. This is the ideal choice for grinding of hard materials or high-volume tool regrinding applications where efficiency and durability is key.
Whilst the abrasive material always defines the cutting characteristics of the wheel, the bonding system holds everything together and, in this case, vitrified bonds offer the best combination of strength and porosity.
Vitrified bonds are fired at high temperatures, resulting in hard, rigid, and porous structures that provide excellent form-holding capability, and facilitates coolant flow and chip clearance, whilst also allowing easy dressing and truing.
Servicing several precision grinding applications, Andor precision tools are driven by performance on demand and are particularly popular. Two of the most well-known applications include internal grinding, and tool and cutter grinding.
Internal Grinding is a machining process used to finish internal surfaces such as bores, and tubes. It is essential in producing components like bearing races, gears, and bushings where high precision and fine surface tolerances are imperative. Given the confined spaces and the complexity of internal geometries, the grinding wheel must maintain balance, deliver consistent material removal, and resist wear.
When it comes applications that require restoring sharpness and accuracy, Tool and Cutter Grinding is the precision grinding application of choice. It involves the sharpening, reshaping, or creating of cutting tools used in CNC machines, milling cutters, drills, and more. Since tool materials often include hardened steels and carbides, grinding wheels must exhibit high hardness, sharpness, and thermal resistance to maintain edge geometry and surface finish.
Apart from demanding accurate and efficient grinding media, precision grinding applications require, tight tolerances, and fine finishes. To achieve this, and prevent damage to the workpiece, heat management is a critical factor during the process.
Andor’s vitrified-bonded wheels deliver superior dimensional accuracy and thermal control, essential for both internal and tool & cutter grinding applications.
For further information contact Grinding Techniques on TEL: 011 271 6400 or email info@grindtech.com or visit www.grindtech.com
