1. ETERNAL company specialize on manufacturing raise boring drill pipe from 8” to 15”, which is applicated to bore all kinds of tunnel and shaft. In the past years, RBM drill pipe ( drill rod )  has been exported to many countries, such ash South Africa, Brazil, Chile, Mexico, Russian, Vietnam, Korea etc, It could be installed on the machine of Sandvik, Atlas Copoc etc.

2. Size and technical specification

3.  Production features

3.1 Choose high strength forging material, including 4140, 4330V, 4330V MOD

3.2 Through quenching and tempering heat treatment, carry out sample test on each piece drill pipe

3.3 CNC turning DI22 thread with high strength, every thread has two starts

4.    Material chemical specification  :

C: 0.28 Min./0.37 Max.        Mn: 0.45Min./0.65Max.          Si: 0.1 Min./0.3 Max.

Ni: 2 Min./3 Max.                  Cr: 0.8 Min./1.1 Max.              Mo: 0.4 Min./0.65 Max.

V: 0.05 Min./0.15 Max.

5.   Mechanical property 

Tensile strength : min 1035MPA    Yield strength : 965MPA 

Impact value :min 90J    

Surface hardness :HB325-365