MOUNTING: The following recommendations are given so that the best results may be obtained in using diamond wheels: Care should be taken in mounting a diamond wheel. Flanges, back plates and spindle should be clean, free of burrs, and run true. By using an indicator and tapping lightly on a wood block held against the wheel, indicate the wheel is within .0005" of the true rotation. Tighten the flanges securely and recheck with an indicator before using. When mounting a cup type wheel, use shims inserted between the back plate and the wheel to obtain a true running face. The use of permanent mounting should be practiced where convenient.
DRESSING & TRUING: Due to the exceptionally free cutting properties of the diamond wheels, frequent dressing is not necessary. They may be dressed with a soft bonded aluminum oxide or silicon carbide dressing stick. When a beveled or gouged condition has occurred in a face type wheel, the wheel may be removed from the machine and rotated in a figurer 8 motion on a glass or cast iron plate sprinkled with 80 to 100 grit silicon carbide dust. To true a peripheral type wheel which has become beveled at the corners, let the diamond wheel revolve at a slow speed mounted on a mandrel between lathe centers and true at right angles with a small silicon carbide wheel mounted on a post grinder.
SPEEDS & FEEDS: The best speeds for diamond wheels for grinding carbide is between 5,000 to 6,000 surface feet per minute. Slightly higher speeds are not detrimental, particularly if a flood of coolant is applied and grinding pressure minimized. Table traverse rates of 100" to 500" per minute with cross feeds of .030" to .060" may be used. The diamond wheel may be used with down feeds of .125" when hand fed across work. For general surface grinding operations, down feeds should not exceed .001" per pass, for rougher grits and .00025" should be used for finish grinding or with fine grit wheels.
COOLANTS: It has been found that a generous flow of coolant increases diamond wheel efficiency. The proper placement of coolant is also important. The coolant must be applied in the proper place or it will not cool the wheel or the material being ground, properly. Coolant should always be directed so that the full flow is at the point of contact between the same direction as the rotation of the wheel.
FOR BORAZON WHEELS
MOUNTING: Unless correctly mounted, BORAZON (CBN) wheels cannot perform well. After mounting, all BORAZON (CBN) wheels, except electroplated wheels, must be correctly trued and conditioned to insure good grinding performance. For the correct mounting of a BORAZON (CBN) wheel, the mounting flanges and faces must be in good condition. To reduce the amount of wheel rim material that has to be removed in truing, the wheel should be mounted as true as possible. With the aid of a dial indicator, it is possible to position the wheel so as to minimize runout. Paper washers, blotters and metal shims should not be used when mounting a BORAZON (CBN) wheel. They make it difficult for the wheel to be held securely on the mount.
TRUING & CONDITIONING: In truing, the wheel rim is cut or abraded with a tool to develop perfect roundness, concentricity with the spindle and the desired profile. In conditioning, bond material is removed to expose the sharp cutting edges of the BORAZON (CBN) abrasive crystals. The following guidelines are general. DO NOT OVER-TRUE THE WHEEL. Accurate truing is important, an out-of-round wheel will pound the work piece, wear fast and produce poor finishes. Excessive truing simply wastes wheel material and shortens wheel life. BORAZON (CBN) wheels are always trued wet, with a flood of coolant applied as directly as possible to the tool/wheel interface. Single-point and cluster type diamond dressing tools should not be used for truing BORAZON (CBN) wheels. They may damage the wheel. One recommended truing tool for BORAZON(CBN) wheels is a metal-bonded nib containing 40-150 mesh diamond abrasive. With this type of tool, truing increments should be in the .0005" to .001" (0,013-0,025mm) range. An alternate to using a diamond nib for truing, is to use a 40/60 grit silicon carbide wheel in a brake-type truing device. Vitrified-bonded wheels with bond hardness in the "J" through "M" range give the best results.
DRESSING & CONDITIONING: Truing glazes BORAZON (CBN) wheels. They will not grind when glazed. Before grinding, they must be conditioned to make them free-cutting. BORAZON (CBN) wheels can be effectively conditioned by abrading the wheel surface with a dressing stick containing fine (220 grit) aluminum oxide abrasive in a "G" to "K" grade vitrified bond. The dressing stick is forced into the wheel quite hard. Usually this is done by hand, but a holding device can be used. A small amount of coolant is used to create a paste or slurry that rolls like grains of sand between the wheel and the dressing stick. This abrades out bonding material which otherwise prevents the wheel from cutting freely. Before dressing, the wheel will feel smooth, while a properly dressed wheel will have a rough texture. Rapid loss of the dressing stick is a good indication that the wheel is being opened.
MATERIALS WHICH ARE EFFECTIVELY GROUND WITH BORAZON (CBN) WHEELS: HIGH SPEED STEELS TOOL & DIE STEELS - CARBURIZED STEELS - NITRIDED STEELS - CAST IRON - BEARING STEELS (52100,M-50 etc.) MARTENSITIC STAINLESS STEELS - COBALT-BASED ALLOYS (STELITES) - UDIMET HASTELLOY - RENE "71" & "77" NICKEL BASED SUPERALLOYS (INCONEL 718) - WASPALOY" - ETC...
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