High quality materialKnurled screw clamp knobs are made of high quality plastic, which is durable and has a long service life. Polished surface for comfortable grip. Clear threadingThe surface threads are deeply stressed and have no residual burrs. The surface of the screws is plated with white zinc, and the color is better. High quality plasticSmooth surface, workmanship high quality,wide application,good resistance to corrosion and rust. Plastic Star DesignThe threaded star head of the tightening knob is comfortable to hold and easy to operate.Easy installation without any tool.You just need to twist it directly by hand to install or remove. Wide ApplicationHand knob threaded star nut M8x40mm are suitable for most general purpose machine tools, such as instruments, electrical appliances, food and equipment industrial. Number of pieces delivered: 10