Formerly, coal passing through bars 3-1/4 to 4-1/4 in (8.3 to 10.8 cm) apart and over 2- 1/4 in (6.7 cm) round holes. In Arkansas, the bars are 7 in (17.8 cm) apart and the holes are 3 to 3-1/4 in (7.6 to 8.3 cm) in diameter.