2014-1-21 · Gravel, dry, sharp 90-100 30-44 15-17 D37 Lignite, air-dried 45-55 30-44 *D35 Rock, soft, excavated with shovel 100-110 30-44 22 D36 Salt, common dry, fine 70-80 25 11 D26TUW Sandstone, broken 85-90 30-44 D37 Wood chips 10-30 45 27 E45WY Coal, anthracite, river, or culm,1/8 inch and under 60 35 18 B35TY
