tools for drilling through rock in tunnels, specifically designed ...

The material used for threaded drill rods is usually high-grade carbon or alloy steel, chosen for their exceptional strength and durability. They are heat-treated to enhance their hardness and resistance to wear and tear, which is crucial given the harsh conditions they face underground. The rods are subjected to rigorous quality control tests, including non-destructive testing (NDT) to ensure their integrity before being deployed.

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