M3-M20 Lock Nuts A2 Stainless Steel All Metal Hex Self-Locking Nut DIN980. Specifications are composed of D, such as: M4 (thread inner diameter 4mm, matching M4 screw) inner diameter needs professional tools to measure. Product name: Hex Self-Locking Nut DIN980. Material: A2 stainless steel. Size: M3 M4 M5 M6 M8 M10 M12 M14 M16 M18 M20. The product is made of A2 stainless steel steel, which has the characteristics of good corrosion resistance, oxidation resistance, heat resistance, high strength and high toughness. A2 stainless steel steel is widely used in seawater equipment, chemical industry, dyestuff, papermaking and other industries. It has a wide range of applications and is popular in various industries. Please allow small errors due to manual measurements. Thanks for your understanding. The monitor is not calibrated and the color of the elements shown in the photo may differ slightly from the actual item. Please refer to the actual product. Package includes: According to your choice. Please select what you want from the drop down menu.