Extension rod, other names are Extension drill steel, Extension drill rod, and Extension steel, M/F rod ( Speed rod ), Produce Hexagonal and round cross sections, Hexagon rods are more rigid, heavier and transfer energy more efficiently, while increasing flushing. Round rods are generally lighter than hexagonal rods and are normally used in extension drilling applications. With the longer steel tending to be larger in diameter, conventional Drifter rod, another names are tunneling steels, tunneling rod, drifting drill rod, has Round and hexagon rod available, most of drifting drill steel with drill Steel Hexagon is for tunneling and drifting drilling application. Hexagon rods are more rigid, heavier and transfer energy more efficiently, while increasing flushing. Main Products: 1-12 inch middle-low/high air pressure DTH hammers & bits Big hole high air pressure DTH hammer using in water well, oil, gas and construction drilling Eccentric overburden drilling Equipment Hole opener bit Rock thread bit (R22, R25, R28, R32, R35, R38, T38, T45, T51, ST58, GT60) Extension Rod, M/F Rod, M/m Rod, Drift Rod, Shank adapter, coupling sleeves and all kinds of adapters Advantages: Compared with the oversea brands, our advantages are bellowing: A. Our products can match over 95% against the original products B. Price are competitive against the famous brands and best quality against the small factory.