Stud bolts Fastenic ST Easy to use and quick to install. Consists of a male expansion plug, sleeve, ring, spring washer and female plug in one piece. can be used to install immediately - No setting tools required - Manufactured from grade A steel, yellow zinc plated. - When tightening the nut according to the specified torque value The surface of the casing expands as it adheres firmly to the concrete hole. - Yellow zinc electroplated anti-rust. - For indoor use