Gaea is a professional manufacturer of rock drilling rod(water well drill rods), Rock drifting and extension drill rods(machining drill rod) are for in drifting, tunneling, long-hole drilling, bench and production drilling industries. These rods are produced with round or hexagonal sections in all common thread designs, and in Male/Male (M/M) or Male/Female (M/F) connections. Please visit https://www.stonedemolition.com/product/extension-drill-rod-drilling-rod-rock-drill-extension-rod for more detail.