Founded in 1981, Grinding Techniques (Pty) Ltd. is the largest privately owned abrasive manufacturer in Africa, operating under the principal business ethos of developing mutually beneficial business partnerships with our valued customers. A wide spectrum of quality Bonded Abrasives are manufactured to ISO 9001:2000 standards; the company also converts Coated Abrasives, and markets Tungsten Carbide Burrs, diamond products and other ancillary items. In addition, Grinding Techniques (Pty) Ltd. is the Southern African agent for Tyrolit abrasives. The company distributes through a network of branches...

FOREWORD TECHNICAL INFORMATION BONDED ABRASIVES 6. Additional Components WHEEL MARKINGS/FLANGE SIZES DIMENSIONS AND SHAPES ISO METRIC STANDARDS FOR GRINDING WHEELS SAFETY IN GRINDING/STORAGE/MOUNTING/RING TEST COATED ABRASIVES/SUPERABRASIVES SURFACE GRINDING: Straight Wheels Cup Wheels and Cylinders Segments EXTERNAL CYLINDRICAL GRINDING INTERNAL CYLINDRICAL GRINDING CENTRELESS GRINDING TOOL & CUTTER GRINDING MINING WHEELS SAW SHARPENING THREAD GRINDING WITH MULTI-RIB WHEELS THREAD GRINDING WITH SINGLE-RIB WHEELS GEAR GRINDING BENCH & FLOORSTAND GRINDING SNAGGING: BENCH, FLOORSTAND AND SWINGFRAME...

Grinding Techniques (Pty) Ltd. was founded during 1981 to supply specialized grinding wheels and abrasive products to the industrial market where a need for quality grinding wheels and allied products had been created through the use of modern specialized wear resistant metals, steels and materials with varying properties. Through persistent research and development coupled with the drive to supply “only the highest quality products” much success was achieved, which inspired the formation of a manufacturing company, “ANDOR GRINDING WHEEL MANUFACTURING CO. (PTY) LTD.”, to produce “Andor” bonded...

BONDED ABRASIVES “Bonded Abrasives” is the name given to the range of abrasive (cutting and grinding) products where abrasive grain is mixed with bonding materials, pressed and fired into various shapes (grinding wheels, segments, rubbing bricks, dressing sticks, mounted points, grinding cones, oilstones etc). GRINDING: is the cutting action of thousands of sharp abrasive grains on the face of the grinding wheel, resembling a complex cutting tool with cutting angles and voids for chip clearance. When closely inspected, the cuttings are identical to those produced by a lathe tool. A secondary...

1. ABRASIVE TYPE There are two basic types of manufactured abrasives, the one is aluminium oxide and the other is silicon carbide. The ideal abrasive for a grinding operation is one which has the following two properties: • Ability to fracture when a serious dullness is reached. • Maximum resistance to pointware. It is obviously difficult to obtain this in a single type of abrasive material. To grind glass, a material of low tensile strength must be used. In this instance silicon carbide abrasive stays sharp longer, and on hardened steel, a material of high tensile strength, aluminium oxide abrasive...

INFORMATION SILICON CARBIDE This type of grain is used for grinding grey iron, chilled iron, brass, soft bronze, copper, aluminium, stone, marble, rubber, hard facing alloys, glass and cemented carbides. There are various types of silicon carbide as in the case of aluminium oxide. 8C - GREEN C - BLACK 6C - BLACK (REFINED) The chart below gives the abbreviated designations (symbols) in accordance with recommendations for the well known Grinding Techniques qualities as well as their characteristics TYPES OF ABRASIVES SYMBOL GRAIN TYPE A Regular Brown Aluminium Oxide 1A Semi Friable Aluminium...

INFORMATION The block shaped crude abrasives are reduced to abrasive grain size by crushing and milling. The abrasive grains are then graded, the range of sizes being internationally standardised according to the sieve mesh size. The grain numeral gives the number of meshes per linear inch. Very fine grains (micro grains) are obtained by sifting and sedimentation. GRAIN SCALE very coarse very fine Coarser grits remove stock more rapidly, but do not leave a good finish. Conversely, finer grits give a better finish, but slower stock removal rates. 3. GRADE (Strength of Bonding) The grade indicates...

HARDNESS (Grades) The expression “wheel hardness” does not refer to the grinding abrasive, but to the “degree of strength” with which the abrasive grains are held in the bond setting of the wheel. The wheel hardness is a measure of the resistance of the bond to the grains being torn out during the grinding process ie. the grain particles will break out of a soft wheel more readily than out of a hard one. As a general rule of thumb, hard workpieces normally necessitate softer grades, and vice-versa. When grinding a hard workpiece with a hard grade, the grain will not be released timeously; it...

Grinding products with porous structure are marked with the letter P and can be further classified as follows: P1 P2 P3 P5 P8 P12 Coarse pores Medium pores Fine pores Very fine pores 5. BOND TYPES There are four basic types of bonds used in making grinding wheels. 1. 2. 3. 4. VITRIFIED BOND RESINOID BOND RUBBER BOND SHELLAC BOND For our purpose, we only look at the following two bonds: VITRIFIED BOND - which is used for over 75% of grinding wheels manufactured. Porosity and strength of wheels made with this bond give high stock removal and their rigidity helps in the attainment of high precision....

INFORMATION WHEEL MARKINGS 31A 60 12 V86 Abrasive Type Grit Size Bond Type Symbols Resinoid Bond A 11A 9A A/C C/A ZA ZZ C 6C Resinoid Bond Reinforced AS CS A/C C/A ZA Extremely soft A B C D Very Soft E F G Soft H BF - Resin reinforced E - Shellac R - Rubber MINIMUM SIZES OF FLANGES FOR STANDARD BORE SIZE WHEELS (Machine must be equipped with sufficient guard) ABCs E REMARKS: 1. The inner face of the flanges must be tapered for a minimum depth of 2 to 5mm depending upon the wheel diameter. 2. We suggest the use of flanges thicker than the recommended size, to allow their re-grinding after...