The following points must be paid attention to when using the electric threading machine
- The electric threading machine has poor precision, large vibration and abnormal operation;
- The alignment of the thread rolling die is not correct, the rolled parts have axial displacement, and the tooth pattern is subjected to two stresses of shearing and extrusion;
- The size of the rolled thread blank is uneven, the surface is not cleaned, and there are grinding wheel foam, oxide skin and dirt;
- The hardness of the rolled parts is uneven (grade 8.8 bolts should be at 27~30HRC; grade 10.9 should be at 35~37HRC) to prevent sometimes untempered high hardness (50~55HRC) quenched parts mixed due to poor management Into the tempered parts, its hardness is similar to the hardness of the thread rolling wheel tooth pattern edge, resulting in chipping.
- Lubricant is not added during rolling, resulting in dry friction, so that the temperature of the tooth tip rises sharply to exceed the tempering temperature of the rolling wheel, and the tooth pattern is softened by excessive tempering, resulting in the failure of inverted teeth and piled teeth;
- The thread rolling wheel must be fully demagnetized before leaving the factory, leaving residual magnetism, and the adsorption of fine iron foam by the tooth pattern during operation will accelerate the wear and failure.