KPMBOLT super nuts adopt a multi-jackbolt tensioning structure with 100% full-process inspection, providing precise preload and anti-loosening performance for reducers, sprocket wheel assemblies and middle troughs of scraper conveyors.
In modern fully mechanized coal mining faces, scraper conveyors are key equipment for coal transportation, traction and material handling, characterized by the heaviest load, harshest environment and most significant impact of failures. During operation, the head and drive sections are subjected to long-term high-frequency vibration, impact and alternating stress. Key components such as reducer flanges, sprocket assemblies, gear rail seats, middle troughs and chain tensioners often experience nut loosening, slipping and breaking, leading to shutdowns, chain deviation, reducer damage and sprocket wear. Traditional lock nuts have limited anti-loosening performance under heavy vibration and load, requiring frequent re-tightening, which fails to meet the demands of continuous production.
German KPMBOLT Super Nuts, backed by nearly 200 years of fastening technology from JUNGEBLODT, adOpting for a multi – jackbolt structure and strict quality control, KPMBOLT has become the most reliable fastening solution for scraper conveyors.
KPMBOLT consists of a nut body, jackbolts, and thrust washers, all produced under a strict Manufacturing and Inspection Process Plan (MPP). The nut body is made of high – quality alloy steel. It comes with a material certificate inspection, has the same batch and heat number, and its chemical composition is verified by a spectrometer. It is free of cracks and defects. It is heat – treated to HRC 30–36, and 100% of it is hardness – tested. The grain size is ≥5 grade, and it is 100% ultrasonic – tested per EN 10308. Jackbolts are made of higher – strength steel, with a hardness of HRC 48–54. They are 100% hardness – tested, have a yield strength of ≥1500MPa, and are 100% magnetic – particle tested per EN 10228 – 1 Level 4. Washers have a hardness of HRC 40–44, and they are precise and defect – free.
The structure provides pure axial preload without torsion, ensuring uniform and stable preload.
On SGZ, SZZ, and other series of scraper conveyors, KPMBOLT is widely used for reducer connections, sprocket assemblies, gear rail seats, middle troughs, and chain tensioners. Its sizes range from M30 to M64 and can directly replace the original nuts without modification. Installation only requires a standard torque wrench, making it suitable for narrow underground spaces. After application, equipment downtime is reduced by over 80%, and the maintenance workload is reduced by 70%. With a Chinese patent and fully traceable quality, KPMBOLT provides safe, stable, and efficient fastening for intelligent mining.
References:
MT/T 187.8—91;
KPMBOLT MPP documents;
JUNGEBLODT techTechnical data; [4] Coal Science and Technology.
