... Hejian Huanyu Petroleum Machinery Co., Ltd. in China.1) Product :we specializes in manufacturing:Tricone bits,steel tooth ... -49080-40187.3~311.17 3/8- 12 1/4490-78480-40mediumHard Shale, Limestone, Medium/Hard Sandstone ... /8294-53980-60187.3~241.37 3/8-9 1/2539-83360-40hardSandy, Shale, Quartzite, Hard Dolomite, ... 8294-53980-40187.3-215.97 3/8-8 1/2580-88260-40Very hardQuartzite, Chert, Basalt Granites, ...