Wholesale Parts Hydraulic Boom Cylinder for Kobelco Excavators
Precision-engineered boom cylinder designed for Kobelco crawler excavators. Forged from high-strength alloy steel and equipped with CNC-machined components, chrome-plated rod, and multi-stage seal kit, this cylinder ensures reliable boom lifting performance in harsh excavation environments.
| 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 boom cylinder is a core actuator that supports vertical lifting and lowering of the boom structure. In Kobelco excavators like SK210LC, SK250-8, or SK330-10, this cylinder must absorb extreme mechanical loads during:
- Material lifting and dumping
- Deep trench excavation
- High-reach demolition or slope work
- Sudden impact from ground or obstacle contact
It operates as the main force channel between the undercarriage and the front-end implement, requiring precise movement, load stability, and fatigue resistance across thousands of cycles.
Material Quality and Structural Design
Our boom cylinders are designed with premium-grade steel and precision tolerances to maintain structural alignment under pressure:
- Barrel: Seamless tubes made of Q345B, ST52, or 27SiMn, honed to < Ra 0.2μm for smooth seal contact
- Rod: Forged 42CrMo piston rod with chrome plating ≥25μm, surface hardness ≥HRC60
- Ends & Pistons: Fully CNC-machined with tight dimensional control (±0.05mm), robot-welded for strength and symmetry
Optional Enhancements
- Bushings with grease grooves
- Reinforced eye clevis with hardened bushing seat
- Port adaptors or welded brackets on request
Internal Cross-Sectional Diagram
This diagram helps visualize how the rod, piston, barrel, and seals interact under pressure, showing key wear zones and sealing points for effective maintenance planning.
Cylinder Manufacturing Process
We follow strict quality workflows, and you can visually demonstrate the process using three key production images：
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 to withstand 1.5× working pressure and checked for leaks, stroke alignment, and valve performance. Final products are sealed and packed in export-grade wooden crates.
OEM Undercarriage Parts for Kobelco Excavator
| BRAND | MACHINERY MODEL NUMBER | |||||||
|---|---|---|---|---|---|---|---|---|
| KOBELCO | SK30 | SK35 | SK40 | SK45 | SK55 | SK60 | SK60-8 | SK60-10 |
| SK75 | SK100 | SK120 | SK120-5 | SK120-6 | SK130 | SK135 | SK135SR | |
| SK135SR-2 | SK140 | SK140SR | SK200 | SK200-3 | SK200-5 | SK200-6 | SK200-8 | |
| SK200-10 | SK210 | SK210-8 | SK210LC | SK220 | SK230 | SK230LC | SK250 | |
| SK250-8 | SK260 | SK260LC | SK270 | SK300 | SK300-6 | SK300-8 | SK320 | |
| SK330 | SK330-6 | SK350 | SK350-8 | SK350LC | SK380 | SK400 | SK450 | |
| SK480 | SK480-8 | SK485 | SK500 | SK500LC | SK850 | SK850LC | ||
Looking for a specific make or model not listed here? Reach out and we’ll be happy to assist.
Compatible Kobelco Excavator Models
This boom cylinder fits a wide range of Kobelco machines, including:
- SK200 / SK210 / SK210LC-8 / SK250 / SK260LC
- SK330-8 / SK330-10 / SK350LC / SK480
- SK300LC / SK320 / SK230SR / SK350SRLC
Unsure which model you have? Just send us your machine type, cylinder casting code, or technical drawing, and we’ll verify the match within 12 hours.
Maintenance & Replacement Tips
- Clean the rod surface regularly and avoid contaminant buildup
- Lubricate pivot ends and check bushing wear periodically
- Replace seal kits every 1,000–1,500 hours depending on site conditions
- Avoid full-stroke impacts or side loading that may damage alignment
Frequently Asked Questions (FAQ)
Q1: Can I replace only the seal kit instead of the entire boom cylinder?
A: Yes. If the rod and barrel are not scored or bent, a seal kit replacement is cost-effective. We supply both cylinders and seal kits.
Q2: Can this boom cylinder work with SK330-8 and SK330-10?
A: Yes, we support both models. Just confirm stroke and pin-to-pin length, and we’ll ensure compatibility.
Q3: Can I customize port size or bushing type?
A: Absolutely. We offer tailored production based on your machine’s hydraulic configuration.
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.
