DIN981/GB912/GB810 M55 Round Nuts

Made from Austenitic stainless 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.

The core function of Stainless Steel DIN981/GB912/GB810 M55 Round Nuts is to achieve high load and anti-loosening axial locking on heavy rotating shafts. It is designed for fixing large bearing inner rings, heavy sleeves or similar key components. Its structural identification feature is that the end face is machined with a precise annular groove. This design must be used in conjunction with a heavy-duty locking washer (stop washer) that meets the standard. By embedding the washer's tongue into the nut groove and anchoring it on the key position on the shaft, an extremely stable mechanical locking system is formed, which effectively resists the risk of loosening caused by high-intensity operation, severe vibration or huge torque of the equipment, ensuring the long-term stable operation of large transmission components.

The nut is made of SS304 stainless steel. Its typical 18-20% chromium and 8-10% nickel composition combination provides excellent corrosion resistance, can resist the erosion of industrial atmosphere, humid environment and various chemical media, and has good machining performance. After solution treatment, the material is non-magnetic, and the surface maintains the natural color of the original stainless steel without additional coating treatment. This feature makes it widely used in fields with strict requirements on material corrosion resistance and strength, such as chemical equipment, large food processing machinery, shipbuilding, heavy machinery manufacturing, and large building structures.

The specific specification is the nominal thread diameter M55, and the coarse thread design is adopted. This thread can better reflect its outstanding load-bearing capacity, high installation efficiency, and good adaptability to manufacturing tolerances in ultra-large diameter applications. There is no special mark on the thread surface (NO MARK). The minimum tensile strength of the nut material reaches 700 MPa. This high strength index is crucial for M55 specification products to ensure that they can bear the huge axial load and tightening force generated in ultra-large equipment. It is necessary to use heavy-duty lock washers of corresponding standards to fully realize the top anti-loosening performance required by its design. This M55 specification and the previously introduced M50/M52 together constitute a complete series to meet the needs of different shaft diameters.