Arm Cylinder Excavators Spare Parts Repair Kit Compatible with Hitachi
Heavy-duty arm cylinder designed for Hitachi crawler excavators. Built with high-strength alloy steel, mirror-honed inner tube, and OEM-grade sealing systems. Delivers stable hydraulic power and long-term durability in mid- to heavy-duty excavation work.
| Cylinder Tube | Q345 / ST52 / 27SiMn / 20# Steel |
|---|---|
| Piston Rod | 45# / 40Cr / 42CrMo (Hard Chrome Plated) |
| Piston | Ductile Iron / Forged Steel (45# / 20Cr) |
| Cylinder Head | Q345 / 45# Steel / Cast Steel |
| Seals | Polyurethane (PU), NBR, FKM |
| Guide Bush | Bronze Alloy / Composite Materials |
| Ports & Fittings | Zinc-Plated Carbon Steel / Stainless Steel |
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Kinton Parts is trusted by professionals worldwide for delivering high-quality parts for excavators, bulldozers, and other construction machinery—with guaranteed performance and durability.
The arm cylinder (also known as the stick cylinder) is responsible for controlling the inward and outward movement of the arm—a crucial action in digging, trenching, and dumping operations. It connects the boom and the arm, converting hydraulic pressure into mechanical motion with consistent force output.
In Hitachi excavators, known for their balanced control and responsive hydraulics, the arm cylinder plays a key role in handling repetitive stress, especially in tasks involving deep trenching, angled digging, or close-quarter loading. A worn or undersized cylinder in this position can result in hydraulic inefficiency, joint vibration, and even accelerated wear in the boom-arm structure.
Materials & Internal Structure
Each arm cylinder is manufactured from forged alloy steel, with Q345B or equivalent grade barrels selected for high pressure containment and fatigue resistance. The piston rod is chrome-plated and polished to resist corrosion and scoring from debris or harsh soil conditions. All components are CNC-machined to ensure structural precision and high-pressure sealing reliability.
- Tube inner surface honed to < Ra 0.2μm
- Threaded ports and ends machined with ±0.05mm tolerance
- Welded joints tested for crack resistance and straightness
These design elements allow the cylinder to perform under tensile and compressive forces during fast arm retraction and extension.
Advanced Sealing System
A high-quality multi-layer sealing system ensures durability and zero leakage under continuous use:
- Buffer seals to absorb pressure spikes
- High-pressure rod seals to hold hydraulic fluid under force
- Dust wipers and wear rings to block contaminants
- End-cap O-rings for static sealing reliability
Sealing kits are selected from NOK, Hallite, or Parker-standard components, giving superior performance across different climates and working conditions.
The diagram illustrates the internal design of a standard hydraulic cylinder—showing the piston, rod, wear rings, and seals. Understanding this layout helps operators and mechanics evaluate wear points and plan timely maintenance or replacements.
Cylinder Manufacturing Process
Below are the key production stages, with real factory photos illustrating each step:
Rod Polishing & Surface Prep
The piston rod is ground and polished to achieve a mirror-smooth surface, ready for hard chrome plating. This step reduces wear on seals and ensures long-lasting hydraulic performance.
Assembly & Sealing
In a cleanroom assembly area, the barrel, piston, rod, and end caps are fitted and torqued to spec. Seal kits are carefully installed to prevent fluid loss and contamination.
Pressure Testing & Export Packaging
Each cylinder is tested at up to 150% of rated pressure to verify sealing integrity. Final units are cleaned, oil-coated, and securely packed in wooden crates for international shipping.
OEM Undercarriage Parts for Hitachi Excavator
| BRAND | MACHINERY MODEL NUMBER | |||||||
|---|---|---|---|---|---|---|---|---|
| HITACHI-EX/ZAX/ZX | EX30 | EX40 | EX55 | EX60 | EX60-2 | EX60-3 | EX60-5 | EX70 |
| EX75 | EX100 | EX100-3 | EX100-5 | EX120 | EX120-1 | EX120-3 | EX120-5 | |
| EX130-1 | EX200-1 | EX200-2 | EX200-3 | EX200-5 | EX200LC-1 | EX200LC-2 | EX200LC-3 | |
| EX200LC-5 | EX220-3 | EX220-5 | EX270 | EX270-1 | EX270-2 | EX270-5 | EX270LC-1 | |
| EX270LC-2 | EX270LC-5 | EX300 | EX300-1 | EX300-2 | EX300-3 | EX300-5 | EX300A | |
| EX300LC-1 | EX300LC-2 | EX300LC-3 | EX300LC-5 | EX330 | EX370 | EX400-1 | EX400-2 | |
| EX400-3 | EX400-5 | EX400LC-1 | EX400LC-2 | EX400LC-3 | EX400LC-5 | EX450 | EX450-1 | |
| EX450-2 | EX450-3 | EX450-5 | EX450LC-1 | EX450LC-2 | EX450LC-3 | EX450LC-5 | UH07-7 | |
| ZAX30 | ZAX55 | ZAX200 | ZAX200-2 | ZAX330 | ZAX450-1 | ZAX450-3 | ZAX450-5 | |
| ZX30 | ZX33 | ZX38U | ZX40 | ZX55 | ZX60 | ZX70 | ZX75US | |
| ZX120 | ZX130 | ZX160LC | ZX200 | ZX210 | ZX240 | ZX270 | ZX330 | |
| ZX360 | ZX400 | ZX450 | ZX470 | ZX500 | ZX650 | ZX850 | ZX870 | |
Looking for a specific make or model not listed here? Reach out and we’ll be happy to assist.
Compatible Hitachi Models
This arm cylinder is designed to fit a broad range of Hitachi crawler excavators, including many of the most popular models in construction and earthmoving sectors:
- ZX200 / ZX200-3 / ZX200-5G / ZX210 / ZX210LC / ZX240LC-3 / ZX240LC-5G
- ZX270 / ZX330 / ZX330-3 / ZX350 / ZX350LC
- EX200 / EX200-2 / EX200-3 / EX200-5 / EX300 / EX300-3 / EX300-5
We also support cylinder customization for regional variants or modified machines.
Not sure about your fitment? Send us your machine model, OEM part number, or dimensional drawing, and our engineers will confirm the exact match for you—usually within 12 hours.
Maintenance Tips for Arm Cylinder Longevity
- Regularly grease pivot points and inspect for rod scratches
- Replace bushings and seals proactively during cylinder service
- Monitor for signs of internal leakage or reduced pushing power
- Avoid sudden arm retraction under full load to reduce fatigue stress
SHIPPING & DELIVERY
At Kinton Parts, we ensure reliable, worldwide shipping of parts for excavators, bulldozers, and a full range of construction machines—safe, fast, and secure.
All products are securely packed using high-quality export cartons, reinforced wooden cases, or industry-standard palletized packaging to ensure maximum protection during transit and smooth handling during unloading.
Standard orders are typically shipped within 3–5 working days, while large or customized orders are usually dispatched within 7–20 days, depending on volume and production requirements.
We offer flexible global shipping options, including:
- International sea freight for cost-effective bulk transport
- Air freight for urgent orders
- Courier delivery (DHL, FedEx, UPS) for small-volume or sample shipments
Our logistics team manages every shipment carefully, providing real-time updates and tracking information until your order arrives safely at your destination.
Need assistance choosing the best shipping method for your location and timeline? Contact our team — we’ll help you plan a smooth delivery experience.
FAQ
Q: What are your main products?
A: We supply a full range of undercarriage and wear parts for excavators, bulldozers, and other heavy equipment. Our product line includes: Track rollers, carrier rollers, front idlers, sprockets, segments, track shoes, track chains, bolt and nuts, pins and bushings, bucket teeth and adaptors, filters, seal kits, swing bearing, and hydraulic cylinder—plus other essential replacement parts.
Q: Which countries do you export to?
A: Kinton Parts exports to over 60 countries worldwide, including:
USA, Canada, UK, Germany, Russia, UAE, Indonesia, Malaysia, Thailand, India, Pakistan, Bangladesh, Sri Lanka, South Africa, Colombia, Peru, and many others.
Q: Can I order a sample?
A: Yes, we accept trial orders. For parts in stock, samples can be shipped quickly. If you have technical drawings or existing samples, we also support customized production and mold development.
Q: How can I track my order after shipping?
A: Once your order is shipped, we will provide you with all necessary tracking information based on the shipping method. For express deliveries, you’ll receive a tracking number to follow the shipment online. For air or sea freight, we’ll send you the relevant documents such as the airway bill (AWB) or bill of lading (B/L), along with the packing list and commercial invoice to help with tracking and customs clearance.
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Trusted by professionals worldwide, Kinton Parts supplies premium-quality components for excavators, bulldozers, and more—with reliable quality you can count on.
