Threaded Interface: The M22 threaded interface ensures standard thread and uniform force, sliding during rotation, providing a safe and efficient drilling experience. Material: Made of forged 45# steel, this extension rod is ideal for electric drills with diamond joints. Its seamless connection ensures a firm connection that resists deformation and eliminates vibration during use. External Sandblasting: The extension rod has undergone external sandblasting, making it waterproof, anti-rust, and wear-resistant. Its construction and high hardness ensure a long service life even in demanding drilling applications. Thick Design: With a lengthened and thickened structure, this extension rod enables a one-step drilling process, providing convenience and efficiency while minimizing the need to change tools. M22 Internal Thread: With an M22 filament internal thread, this extension rod is compatible with most M22 filament water drills, ensuring wide use and compatibility for various drilling tasks.