DIN981/GB912/GB810 M25 Round Nuts

Made from Austeniticstainless steel, they contain about 18-20% chromium and 8-10% nickel, offering exceptional corrosion resistance and good machinability.In the chemical, petrochemical, and food processing industries, SS304 nuts are favored due to their corrosion resistance and hygiene properties. They are also widely used in medical devices, architectural decorations, and machinery.

Stainless steel DIN981 is the German industrial standard for slotted round nuts, commonly used for bearing locking and mechanical shaft-end positioning. GB912 and GB810 are Chinese national standards for similar round nut structures, with designs and applications largely consistent with the DIN standard. M25 indicates a nominal thread diameter of 25 millimeters, typically used in medium-sized mechanical equipment.

Structural Features
1.Round shape with slot design: The nut has two or four evenly spaced slots on its outer surface, allowing for tightening or removal with special tools such as hook spanners.
2.High precision grade: Suitable for high-precision bearing housings and locations where reliable locking is required.
3.Various locking methods: Can be used with lock washers (e.g., DIN5406) to enhance resistance to loosening.
4.Metric fine thread: The fine thread form ensures stable connections even in environments with strong vibrations.

DIN981 / GB912 / GB810 M25 round nuts are commonly made from carbon steel (such as 45#), alloy steel, or stainless steel (such as 304 or 316), meeting different strength and corrosion resistance requirements. Surface treatments such as black oxide, zinc plating, Dacromet coating, or nickel plating can be applied depending on the service environment to enhance corrosion and wear resistance. These round nuts are widely used for shaft-end locking and fastening in various mechanical applications, such as bearing retention on precision machine tool spindles, securing motor bearing end caps, connecting shaft-end components in gearboxes, fans, and pumps, as well as positioning and fastening rotating shaft components. With reliable axial preload and stable locking structures, these nuts effectively prevent loosening and axial displacement, ensuring the operational stability and service life of the equipment.