M341256 Original Excavator Parts Socket Bolt for Hitachi

The original hexagon socket bolt M341256 is a specialized fastener for Hitachi ZX series excavators (such as ZX120, ZX210, ZX230, ZX240LC, ZX270, ZX330, ZX360LC, etc.), and the universal number is its part number. This bolt is usually used for connecting key parts such as rotating devices, walking devices, fuel tanks, and supporting wheels. Its thread specifications (such as M12, M14, M16, etc.), length, and strength grade are all matched with the design load of the main engine. When ordering or replacing, it is necessary to verify the universal number and refer to the maintenance manual of the corresponding model to confirm the installation position and torque requirements, in order to ensure the reliability of the connection and the safety of the entire machine.

This product is forged from high-strength alloy steel (commonly 35CrMo or 42CrMo), and after quenching and tempering heat treatment, the hardness reaches 32-39HRC. The strength grade is mostly 10.9 or 12.9, and it has excellent tensile, shear, and fatigue resistance properties. The head is cylindrical and embedded with precision hexagonal holes (commonly 10mm, 12mm, 14mm, etc.), which need to be installed with an internal hexagonal wrench. The surface is often treated with Dacromet or galvanizing, which has strong corrosion resistance. The threaded part is formed by rolling, with precision in accordance with ISO4762 or DIN912 standards, ensuring that the pre tightening force can still be maintained under severe vibration conditions of the excavator to prevent loosening.

Before installation, it is necessary to thoroughly clean the bolts and threaded holes, remove oil stains and rust, and check whether the threads are intact. It is necessary to use a torque wrench to tighten according to the torque values specified in the Hitachi maintenance manual (for example, the bolt torque of the ZX120 rotary device is 490N · m, and the bolt torque of the walking device is 305N · m). Every 250 hours of daily work, key bolts should be checked for looseness. If a decrease in pre tightening force is found, it should be re tightened in a timely manner. Strictly prohibit tightening with excessive torque or using impact wrenches to avoid bolt tension and thread slippage. If there are cracks, deformations, thread wear or severe corrosion in the bolts, the original M341256 parts should be replaced immediately. Ordinary bolts cannot be used as substitutes to avoid affecting the structural integrity of the entire machine. When storing, it should be placed in a dry environment to avoid damaging the threads due to collision.