procurement of 06 numbers of grinding ring and 216 numbers of ball of el-76 pulveriser at unit-2, btps. , procurement of 06 numbers of grinding ring and 216 numbers of ball of el-76 pulveriser at unit-2, btps. , top grinding & bottom grinding ring additional data: technical specification of the rings (each set) a) 01. top grinding rings: conforming to drawing no. bndl/mech/60/a in hi-chrome. hardness: 580 to 625 bhn. 02. bottom grinding rings: conforming to drawing no. bndl/mech/59/a hi- chrome. a threaded groove to be moulded in the bottom grinding ring so as to facilitate commissioning of wire brush assembly. n.b. finished casting shall be free from blow holes. dents are to be fitted to give smooth finish. careful machining shall be done so as to full fill the specification & drawings. deviation from specified limits of machining shall in no case be acceptable. the bottom shall have to be fitted within m.s. band ring of 25 mm thickness. hardness: 580 to 625 bhn.(min.) , hollow grinding ball, size:12-1/4 for pulveriser el-76 unmachined hollow grinding balls for el-76 pulveriser, size, o.d.-12-1/4 additional data: technical specification of unmachined hollow grinding balls for el-76 pulverisers duly cast heat treated. material composition: high chrome hardness: min. 580bhn. the out of roundness of the balls shall be within 0.120 on the diameter. size: (a) 12¼ o.d. (one set = 18 nos.) , gst, if any