- Set of 6 threaded ball knobs with 40mm diameter, perfect for replacement in industrial machinery and professional equipment. - Made of high-quality phenolic plastic with iron insert, ensuring structural strength and stability. - M12 female thread compatible with a wide variety of machines and tools. - Ergonomic spherical design that facilitates grip and rotation, improving the user experience. - Polished and smooth surface for a professional and safe finish. - Ideal for textile, woodworking, printing, agricultural machinery, sports equipment, and more. - Offer excellent mechanical strength, wear resistance, heat resistance, and electrical insulation. - High impact resistance, do not deform easily, and have a long service life.