Machinery's Handbook, 31st Edition
CYLINDRICAL GRINDING 1317 list of grinding wheel recommendations with general validity. Instead, examples of recommendations embracing a wide range of typical applications and assuming common practices are presented in Table 2. This is intended as a guide for the starting selection of grinding wheel specifications which, in case of a not entirely satisfactory performance, can be refined subsequently. The content of the table is a version of the grinding wheel recommendations for cylindrical grinding by the Norton Company using, however, non- proprietary designations for the abrasive types and bonds. Table 2. Wheel Recommendations for Cylindrical Grinding Material Wheel Marking Material Wheel Marking Aluminum SFA46-18V Forgings A46-M5V Armatures (laminated) SFA100-18V Gages (plug) SFA80-K8V Axles (auto & railway) A54-M5V General-purpose grinding SFA54-L5V Brass C36-KV Glass BFA220-011V Bronze Gun barrels Soft C36-KV Spotting and O.D. BFA60-M5V Hard A46-M5V Nitralloy Bushings (hardened steel) BFA60-L5V Before nitriding A60-K5V Bushings (cast iron) C36-JV After nitriding Cam lobes (cast alloy) Commercial finish SFA60-18V Roughing BFA54-N5V High finish C100-1V Finishing A70-P6B Reflective finish C500-19E Cam lobes (hardened steel) Pistons (aluminum) SFA46-18V Roughing BFA54-L5V (cast iron) C36-KV Finishing BFA80-T8B Plastics C46-JV Cast iron C36-JV Rubber Chromium plating Soft SFA20-K5B Commercial finish SFA60-J8V Hard C36-KB High finish A150-K5E Spline shafts SFA60-N5V Reflective finish C500-I9E Sprayed metal C60-JV Commutators (copper) C60-M4E Steel Crankshafts (airplane) Soft Pins BFA46-K5V 1 in. dia. and smaller SFA60-M5V Bearings A46-L5V over 1 in dia. SFA46-L5V Crankshafts (automotive Hardened pins and bearings) 1 in. dia. and smaller SFA80-L8V Finishing A54-N5V over 1 in. dia. SFA60-K5V Roughing & finishing A54-O5V 300 series stainless SFA46-K8V Regrinding A54-M5V Stellite BFA46-M5V Regrinding, sprayed Titanium C60-JV metal C60-JV Valve stems (automative) BFA54-N5V Drills BFA54-N5V Valve tappets BFA54-M5V Note: Prefixes to the standard designation “A” of aluminum oxide indicate modified abrasives as follows: BFA = Blended friable (a blend of regular and friable), SFA = Semifriable. Operational Data for Cylindrical Grinding.— In cylindrical grinding, similarly to other metalcutting processes, the applied speed and feed rates must be adjusted to the operational conditions as well as to the objectives of the process. Grinding differs, how- ever, from other types of metalcutting methods in regard to the cutting speed of the tool which, in grinding, is generally not a variable; it should be maintained at, or close to the optimum rate, commonly 6500 feet per minute (1980 m/min) peripheral speed. In establishing the proper process values for grinding, of prime consideration are the work material, its condition (hardened or soft), and the type of operation (roughing or finishing). Other influencing factors are the characteristics of the grinding machine (stability, power), the specifications of the grinding wheel, the material allowance, the rigidity and balance of the workpiece, as well as several grinding process conditions, such as wet or dry grinding, the manner of wheel truing, etc.
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