Check the listing for details. 6Pcs Knurled Thumb Nuts, M6x12mm Carbon Steel Nut Iron Round Knobs Black. Condition: New. Listed at 11.32 USD. What is this?These round knob fasteners can be widely used in the machinery industry, furniture fastening, 3D printer beds, and other electrical or industrial products.What will I get? Color: Black;Material: Carbon Steel;Thread Size: M6 x 1mm (Dia*Pitch);Height: 12mm/0.47 inch;Outside Diameter: 20mm/0.79 inch;Style:Step hand tightening nut;In the package of: 6Pcs screw inserts for 3D Printer;Are there any advantages of the product?Knurled thumb nuts are designed with clean, compact, and accurate thread, which makes it not easy to be out of shape or slide in the process of rolling.Knurled nuts are strong and durable and suitable for long-term use. The carbon steel is anti-oxidation and does not hurt the hands. Stable Structure: internal and external teeth are evenly stressed, and the structure is more stable.