threaded shaft 3d model

Create a precise 3D model of a cylindrical mechanical shaft with a total length of 650 mm and an outer diameter of 30 mm. The shaft must have external threads on both ends. Each threaded section should be metric thread type M20 (or specified M thread), with a thread length of 10 mm on each side. Ensure the threads are accurately modeled with realistic pitch and profile according to ISO metric standards. The central part of the shaft remains smooth (unthreaded), with clean surface finish and slight chamfers (1–2 mm) on transitions between threaded and non-threaded sections. Apply realistic steel material with machining marks. Maintain perfect cylindrical symmetry and engineering precision. Include optional details: small edge fillets, thread relief grooves near the thread ends, and dimensional accuracy suitable for manufacturing. Render in high resolution with neutral studio lighting, CAD-style visualization, 4K quality.