... feedshell which supports a percussion drill, drill rod assembly, and a centralizing drill rod support disposed between the percussion drill and a ... stationary forward end drill rod support.(1)Material/Grade:DIN CK45, JIS S45C, SAE1045, ... (0.43-0.55)(4)Length:Blasting furnace Tap hole drilling rod: 1.0m-6mWe serve customized design, production and serve according ...