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Manufacture Of Extra Large Hexagon Nuts
- Jan 18, 2019 -

Manufacture of extra large hexagon nuts

With the rapid development of modern industry and the need of practical production, the demand for fasteners is also expanding to high, fine and large.The so-called "high" is high strength requirements, workpiece manufacturing choice material mechanical properties, "fine" is the workpiece manufacturing technology precision and quality requirements, "big" is the product specifications.

GB/ t6170-6175-2000 hexagon nut specifications range from the shape of M15~M64 nuts and geometric size, but this series of standards are not able to meet the needs of practical application at this stage, there are considerable products have been far beyond the range of the standard series, belongs to the specification of the workpiece, referred to as extra-large nuts.

For example, the complete set of nuts and bolts on the foundation of the tower crane of construction machinery, the specifications include M68, M72, M76, M80, M90, M95 and other six specifications, the material is 35CrMoA, and the mechanical performance requires grade 8.To produce extra large nuts of this size requires a special manufacturing process.Due to the large size, it is difficult to use cold heading or die forging in friction press.

Finally, we selected the rough forging shape of free forging -- a six-prism body with little machining allowance, and the processing method of cutting and splitting into single nut forming (the machining allowance is no longer required if the contour precision is not high), and successfully completed the production task.