KPMBOLT super nuts are specially designed for hydraulic supports. They undergo 100% full inspection and can achieve stable locking for flanges, four – link mechanisms, and jacks.
Hydraulic support is the core safety equipment in fully mechanized mining faces, bearing roof pressure, surrounding rock deformation, and mining impact. Under long – term reciprocating load, side stress, impact, and the humid underground environment, key parts such as column flanges, four – link mechanisms, balance jacks, and bases often experience nut loosening and preload attenuation, leading to support deviation, leakage, and even support failure.
Traditional nuts rely on friction and easily loosen under alternating load, requiring frequent maintenance and reducing mining efficiency.
German KPMBOLT Super Nuts, with a multi – jackbolt structure and strict quality control, provide reliable, maintenance – free fastening for large – cutting – height and intelligent hydraulic supports.
KPMBOLT consists of a nut body, jackbolts, and washers, all under the full Manufacturing and Inspection Process Plan (MPP). The nut body is made of high – strength alloy steel with a material certificate, from the same batch and heat number. Its chemical composition is verified by a spectrometer and complies with GB/T 3077. It is heat – treated to HRC 30–36, with 100% hardness testing, a grain size of ≥5 grade, and 100% UT testing (EN 10308 Level 4). Jackbolts are made of higher – grade steel, with a hardness of HRC 48–54, 100% hardness testing, a yield strength of ≥1500MPa, and 100% MT testing (EN 10228 – 1 Level 4). Washers have a hardness of HRC 40–44, are precise, and defect – free. Pure axial preload ensures uniform force and eliminates loosening.
It is widely used in column flanges, four – link mechanisms, jacks, and bases. Sizes range from M30 to M64, and they can directly replace the original nuts, with easy installation. The failure rate is reduced by over 90%. With a Chinese patent and fully traceable quality, KPMBOLT meets coal mine safety standards.
As intelligent mining develops, KPMBOLT provides safer and more stable fastening for hydraulic supports.
References:
- MT/T 516.1—1995;
- KPMBOLT MPP documents;
- JUNGEBLODT technical data;
[4] Journal of China Coal Society.
