High - quality bolts and nuts must be used in mining systems as they have to withstand extreme stress.
Statistics show that in large mines, the bolts and nuts at the connection parts of equipment often need to bear a tensile force of over 300kN. If the quality is poor, the risk of fracture is extremely high. For example, in 2018, the connection bolts and nuts of a crusher in a copper mine broke due to insufficient strength, resulting in the sudden stop of the equipment, the paralysis of the production line for a week, and a direct economic loss of over $3.5 million.
What are the best bolts and nuts for mining systems? When purchasing bolts and nuts, factors such as their strength, corrosion resistance, anti - loosening performance, wear resistance, and toughness should be considered.
What Constitutes the Best Bolts and Nuts for Mining Systems? High Strength is the Most Crucial Factor
In mines, the bolts and nuts of mining equipment are subjected to huge stress. For instance, when the bucket of a large - scale mining excavator is digging, the bolts and nuts at the connection parts need to bear a tensile force and shear force of up to tens of thousands of Newtons. If the bolts and nuts have insufficient strength, they are prone to fracture, leading to serious accidents.
Therefore, the purchased bolts and nuts should have excellent tensile strength and yield strength. According to data in "China Mine Machinery Engineering", in the mining operations of some large - scale open - pit mines, the axle - connecting bolts and nuts of mining trucks need to bear a tensile force of over 500kN, and the required tensile strength should reach above 800MPa.High Corrosion Resistance
In some specific mining environments, bolts and nuts should have high corrosion - resistant properties. Especially in the humid environment of mines and in soil containing acids and alkalis, bolts and nuts should be able to resist corrosion for a long time. You can verify the corrosion resistance of products through the salt - spray test. Theoretically, they should show no obvious corrosion phenomena for at least 1000 hours.
Research by the National Association of Corrosion Engineers (NACE) shows that in mines without anti - corrosion measures, ordinary carbon - steel bolts and nuts can corrode within 3 months, and their load - bearing capacity will decline.Good Anti - loosening Performance
As
fasteners between equipment, bolts and nuts should be very firm and not easy to loosen. Therefore, in common mining scenarios, such as the vibrations of vibrating, impact, and crushing machines, high - quality bolts will not loosen, and the anti - loosening torque loss rate should be less than 10%.
According to relevant research by China University of Mining and Technology, in a vibration test with a vibration frequency of 50Hz and an amplitude of 5mm, by using locking nuts and spring washers with special anti - loosening designs, the anti - loosening torque loss rate can be controlled at a relatively low level, improving the overall system safety of mining operations.
High Wear Resistance
The mining system will be maintained within a specific period, and bolts and nuts are required to have good wear resistance. Especially when they are assembled and disassembled, they are prone to wear, making the connection between equipment unreliable.
Research in "Tribology" shows that under the simulated assembly and disassembly working conditions of
mining equipment, bolts and nuts made of high - hardness and wear - resistant materials can still control the thread profile wear within 0.1mm after 100 cycles of loading and unloading, and the wear coefficient is higher than 0.8.
High - temperature Resistance
For mines at normal temperature, high - temperature resistance is not a necessary property for bolts and screws.
However, in some deep - underground mines, the area may be close to the geothermal source (especially in areas with hot springs), and the ambient temperature will rise suddenly. This requires the use of specific high - temperature - resistant equipment, bolts, and screws to avoid fastener failures.
In addition, in the high - temperature smelting process of certain mining techniques, the high - temperature resistance of screws and nuts is essential. According to data from an internationally authoritative materials research institution, screws and nuts made of high - temperature - resistant alloy materials have a decline in mechanical properties of no more than 15% in an environment above 300°C, with high safety performance.Good Toughness
In mining operations, equipment may be impacted by sudden ore falls or collisions between equipment. If the
bolts and nuts lack toughness, even if they have high hardness, they are prone to brittle fracture.
In addition, mining equipment is often used for a long time, making it prone to metal fatigue. Therefore, when purchasing mining spare parts, you should ask the supplier about the toughness of the parts.
According to data in "Mechanical Design Manual" published by China Machine Press, for screws and nuts used in
mining equipment, the impact toughness value requires an impact absorption energy of over 50J.
Tianlong Fasteners: A Trustworthy Manufacturer of High - quality Bolts and Nuts
Tianlong
fasteners Company has significant advantages in the manufacturing of
mining bolts and nuts. Relying on advanced production equipment and scientific processes, the company can manufacture high - strength alloy steel and stainless - steel bolts and nuts.
Its products have high tensile strength, and its customized R & D capabilities can provide specific bolt and
nut products for extreme working conditions such as high - temperature, high - humidity (85% RH), and vibration (50Hz, amplitude 5mm) in mines, improving mining efficiency.
