1. For a 10 kg flange, the number of holes is 4 when the nominal diameter is in the range of 40-65 mm; 8 when the nominal diameter is in the range of 80-150 mm; and 12 when the nominal diameter is in the range of 200-300 mm.
2. For a 16 kg flange, the number of holes is 4 when the nominal diameter is in the range of 40-80 mm; 8 when the nominal diameter is in the range of 100-200 mm; and 12 when the nominal diameter is in the range of 250-300 mm.
