ABRASIVE TECHNICAL INFORMATION - …

1 ABRASIVE FINISHINGA brasive finishing combines a harder than workpiece ABRASIVE mineral combined witha bonded or coated product that is rubbed or moved with pressure across theworkpiece surface. ABRASIVE finishing can produce a visual or mechanical finishon metals, composites, stone, glass or wood ABRASIVE finishing processes can be achieved by hand, portable equipment,manual or automated machinery. Processes include grinding, polishing, buffing,lapping and affects from the ABRASIVE finishing process VISUAL MECHANICALSoft brushed!!!!!DeburringGrained!!!!!Surface refinementSwirled lines!!!!!Surface preparationNon directional random scratch!!Radiusing Statin!!!!!!PeeningBright reflective(buffed)Factors that affect ABRASIVE finishing1. ABRASIVE minerals type, size, shape ad hardness2.

2 Bonding types3. Cutting speed4. MachineryABRASIVE TECHNICAL INFORMATION1. Mineral Type (most commonly used)ALUMINUM OXIDE (AL2O3) is a man made heat treated fusedalumina bauxite produced in electric-arc furnaces at temperaturesexceeding 4,000 degrees Fahrenheit. After heating and then cooling,the mineral is crushed and sized and is available in grit sizes from6 to 1200 and finer. Aluminum oxide (A/O) has a blocky structurethat when fractured maintains a sharp edged blocky shape. A/O shardness is 9 on the Mohs scale. A/O is one of the widest usedabrasive mineral because of its toughness and durability. It s usedto finish metals, composites, and CARBIDE (SIC) or carborundom is a naturally occurringbut mainly man made ABRASIVE produced by heating or fusingsilicon and carbon in vast outdoor facilities. Silicon carbide (S/C)has a sharp slivery shape and is more friable than aluminum hardness is on the Mohs scale.

3 S/C is widely used forfinishing hard metal, glass and ceramic ABRASIVES is a man made non metallic crystalline structure producedby heating and cooling ceramic matrixes. Ceramic abrasives are very tough, hardand long lasting with a life of 2-3 times that of aluminum oxide. Ceramic abrasivesare used on hard metals and long ABRASIVE life requirements. Higher pressures arerequired to fracture the ceramic ALUMINA is a man made aluminum oxide enhanced with approximate20% zirconium oxide. The zirconia increases the strength of the aluminum oxideby stress induced transformation toughening. Zirconia is stronger, tougher with lifeup of 1-1/2 to 2 times that of aluminum oxide. Zirconia is blocky or cubic in structureand is a good choice when longer life or tougher abrasives are required. Mostapplications are in the coarser grits between 24 and 120 grits.

4 The finish iscoarser than that of the same grit size of aluminum And CBN ABRASIVES are naturally occurring and can be produced synthetically in a high pressure and high temperature process. Most diamonds that are mined are used industrially and most diamonds used in industry are synthetic. Diamondabrasives are used because of their hardness which is a 10 on the Mohs scaleand because of their thermal conductivity. Diamonds have a face cubic diamond abrasives are used in hard grinding wheels, powders and coatedabrasives and are used on hard steels, ceramics and interrupted cutting of TECHNICAL INFORMATIONEMERY ABRASIVE is a naturally occurring aluminum oxide mixed with otherminerals such as silica. The black color material is mined. The hardness rangesbetween 6-8 on the Mohs scale. The softer ABRASIVE is used in emery boards,emery cloth, and polishing abrasives reducing polishing line ABRASIVES utilize the fine grades of aluminum oxide and silicon carbide abrasives.

5 Buffing also uses fine graded calcined alumina, Tripoli, iron oxide and chrome oxides abrasives that are carried by greaseless or tallow based materials forced into the buffing wheels( which acts as the ABRASIVE carrier) or sprayed onto the buffs of automated SIZEA brasive size, referred to as grits, affects the amount of work achieved as well as the finish ABRASIVE sizes range between 8-60 grit. Coarser grits remove significant material and leave coarser finishes. The coarser grit sizes are a good choice for large weld removal, de-flashing, and de-gating castings, and removal of largeamounts of ABRASIVE sizes range between 80-150 grits. Medium grits will also removea fare amount of material and leave finer and paintable surfaces. They are alsogood for spot weld removal, radiusing, deburring and finer weld ABRASIVE sizes range between 180-400 and super fine up to1200 grits, The material removal is less but are capable of maintaining good rms finishes.

6 The finer abrasives removescratches in paint and are used in lapping, polishing prior to buffing, and fineradiusing with very pleasant appearances GRIT SIZES FOR COATED ABRASIVES AND RELATED RMS FINISH CAPABILITIESWhen producing coated abrasives products (belts, discs, paper) the ABRASIVE manufacturers of American, Europe, and Asia have slightly different ABRASIVE grain size standards. The ISO standard FEPA designated with a P is the European designation and the CAMI is the American.

7 Below is the size range variances and approximate finish capabilities. The RMS (root means squared surface measurement) average range is calculated at 1/2 life ABRASIVE on coated products. Belt grease and lubricants will reduce RMS readingsABRASIVE TECHNICAL INFORMATION ISO/FEPA Grit Standard CAMI Grit Standard Mircon size RMS Finish designation designation average Aluminum oxide 1/2 Course P12!!!!!! 1815 Grits P16!!!!!! 1324 P20!!!!!! 1000 P24!!!!!! 764 24!! 708 P30 642 30!

8 ! 632 P36 538 36!! 530 P40 40!! 425 50!! 348 100 RMS P50 336 60!! 265 95 RMS P60 269 Medium P80 201 Grits 80!! 190 70 RMS P100 162 100!

9 ! 140 60 RMS P120 125 120!! 115 45 RMS P150 100 150!! 92 35 RMS Fine grits P180 180!! 82 20 RMS P220 220!! 68 15 RMS P240 59 240!! 53 P280 52 P320 46 P360 41 320!

10 ! 36 8 RMS P400 35 P500 30 360!! 41 P600 36 400!! 23 SuperFine P800 22 Grits 500!! 20 P1000 18 600!! 16 P1200 P1500 800!