Hand-held rock drills are generally used in foreign granite and marble mines as manual trimming of blocks, drilling anchor holes for large rock drilling equipment such as gantry rock drills, and hand-held rock drilling machines for auxiliary operations in mines; In China, it can also be used for drilling the intersection holes with a depth of less than 6m and threading beaded ropes. However, in the former granite mines in Brazil, now India and Russia and other countries, a large number of hand-held rock drills are used to drill vertical rows of holes to separate long blocks of stones. The hand-held rock drill usually drills a row of holes to a depth of about 6-9m, and sometimes can drill a deep hole of 12-18m. The hole spacing of drilling is related to granite splitting, drilling direction and drilling purpose, generally between 10-60cm. The hand-held rock drill uses standard diameter (32-42mm) drill bits and drill rods (up to 6.4m) to drill rows of holes, and the drilling speed of drilling medium hardness granite is about 5-10cm/min; drill rods can also be used to connect The sleeve is used to drill deep holes with a depth of more than 6m or 9m after connecting drill rods of different lengths. Due to the excessive length, the drill rods are often stuck in the drilled holes. Only after the stones of equal length are overturned can they be taken out. In a purple-point white hemp granite mine of Guidoni Company in Brazil, there used to be a vertical row of holes with a depth of 46m, and a vertical row of vertical holes with a depth of 53m was successfully drilled. Because of the large drilling depth, the mine used a special 35kg hand-held The rock drill is used for manual drilling. The maximum vertical drilling depth of the rock drill is 60m and the drilling speed is 0.8m/min.
