J901240 Original Excavator Parts Bolt for Hitachi ZX120 ZX200-3 ZX330 ZX330-3 

The bolt with part number J901240 is a high-strength fastener certified by Hitachi. According to the Hitachi parts system, this bolt is likely to be widely used in the Hitachi ZX and EX series of medium to large crawler excavators, such as common models such as ZX200, ZX210, ZX240, ZX300, ZX330, ZX360, ZX450, as well as corresponding older models such as EX200, EX220, EX300, etc. It is usually used for connecting key structural parts, such as engine mounts, slewing supports, articulated points between the boom and platform, high-strength connections between track chains or large structural components. Due to the direct impact of bolt specifications (such as diameter, length, thread type) and strength grade on its adaptability, specific equipment models, serial numbers, and clear photos or detailed dimensional measurement data of old bolts must be provided before procurement for accurate matching.

As an original high-strength bolt, J901240 is usually made of alloy structural steel (such as 40Cr, 42CrMo or similar materials), which is subjected to quenching and tempering heat treatment to achieve a high-strength grade of 10.9 or 12.9, in order to meet the extreme stress requirements of excavators under heavy load, impact and vibration conditions. The surface treatment process may include phosphating, Dacromet or galvanizing to provide excellent rust and corrosion resistance. The dimensional accuracy of bolts is strictly controlled to ensure smooth thread fit and even transmission of pre tightening force. The original parts are designed with full consideration for anti loosening performance, and may use fine thread, flanged surface, or be used in conjunction with specific anti loosening washers.

The maintenance core of this bolt lies in standardized installation, regular inspection, and preventive replacement. Installation specifications: A calibrated torque wrench must be used during installation, and the torque values and tightening sequence (such as step-by-step or cross tightening) specified in the maintenance manual must be strictly followed for tightening; Ensure that the threads are clean and undamaged, and apply an appropriate amount of thread locking agent or designated lubricant to the threaded area (unless the bolt itself has been pre coated). Regular inspection: It is recommended to visually inspect and torque recheck all high-strength bolts in critical areas every 500 working hours or during regular maintenance to check for signs of looseness, rust, cracks, or tensile deformation.