Description
Truck Crane Outrigger Rack Opening Cylinder
Precision-engineered at Φ70×1237mm with 20 MPa working pressure — built for UK construction fleets, crane hire operators, and heavy plant engineers who cannot afford downtime.
Φ70×Φ50×1237mm
20 MPa / 30 MPa Max
Weight: 48 kg
How the Rack Opening Cylinder Works
The outrigger rack opening cylinder is a single-stage, double-acting hydraulic actuator mounted within the outrigger box beam of a truck crane. When the crane operator actuates the outrigger extend function from the cab, pressurised hydraulic fluid — typically at 20 MPa — enters the cylinder’s cap end, extending the 1237 mm stroke piston rod outward. This mechanical extension pushes the outrigger rack slide outward from the crane’s chassis, creating the wide support footprint the crane needs to safely lift rated loads. On retraction, fluid enters the rod end, pulling the rack back into the boom body.
What makes this particular design robust is the combination of a hardened and chrome-plated Φ50 mm rod — which resists surface wear, corrosion from UK weather exposure, and side-load bending — with a precision-honed Φ70 mm bore barrel that maintains dimensional tolerance after thousands of full-stroke cycles. The cylinder seals are selected for low-temperature performance, critical for winter site operations in northern England or Scotland, and the end fittings are machined to close tolerances to eliminate play that could produce knocking under load reversal.
Materials & Construction Standards
Every cylinder leaves the factory only after completing a full cycle test at 30 MPa — the rated maximum withstand pressure — to verify seal integrity, rod straightness, and port thread condition. The barrel bore is inspected with a calibrated air gauge to ensure roundness is within 0.02 mm. These are not nominal figures; they are minimum-pass criteria that every unit must meet before receiving a serial-numbered quality certificate shipped with the product.
Technical Specifications — HCYY11112022
| Cylinder Model | Specifications | Working Pressure | Maximum Withstand Pressure | Trip (mm) | Installation Distance (mm) | Weight |
|---|---|---|---|---|---|---|
| HCYY11112022 | Φ70×Φ50×1237 | 20 MPa | 30 MPa | 1237 | 140 | 48 kg |
Where This Cylinder Performs in the UK
Truck cranes fitted with rack-type outrigger extensions are standard equipment across a broad range of British heavy industry and civil infrastructure sectors. This cylinder is directly applicable as an OEM-replacement or upgrade component for any truck crane that uses a rack-slide outrigger mechanism — it is not a universal part, but it is engineered to be adapted with modest machining to fit a wide range of chassis sizes.
Why UK Engineers Specify This Cylinder
Truck Crane Cylinder Series
The rack opening cylinder is part of a broader truck crane hydraulic cylinder family engineered to the same 20 MPa working standard. Whether you need luffing cylinders, boom extension cylinders, or outrigger pad cylinders, we manufacture and supply the full range with consistent quality standards across every SKU.
Also Available — Forklift Attachment Cylinders
For warehouse and logistics operations requiring hydraulic cylinder replacements across your forklift attachment fleet, we supply purpose-built attachment cylinders in multiple duty ratings:
Customer Success: Midlands Crane Hire, United Kingdom
Client: Midlands Crane Hire Ltd — a 34-unit mobile crane fleet operator based in Coventry, serving construction contractors across the East and West Midlands.
Challenge: Three of their 25-tonne truck cranes suffered outrigger rack cylinder failures within the same season — two from seal degradation caused by extended cold-weather idling, one from rod surface pitting attributed to road salt ingress. Downtime per incident averaged 6 working days including sourcing OEM replacements from Germany, costing the company over £14,000 in lost hire revenue and expedited freight.
Solution: They trialled two HCYY11112022 units as direct replacements, fitted by their in-house hydraulic engineer. The cylinders arrived within 12 working days from order, complete with test certificates and dimensional drawings. Fitting required no modification — the installation distance of 140 mm matched their existing chassis mounting.
Outcome: Both units have completed 14 months of continuous fleet operation with zero leaks, zero rod scoring, and consistent full-stroke extension in all ambient conditions including recorded temperatures of -8°C during a January project in Derbyshire. They have since placed a standing order for six units as preventive stock.
What Clients Say
“We’ve been through three different suppliers for this cylinder spec. These are the first ones that came with actual test certs and fitted perfectly straight out of the crate. Sixteen months in, both still tight.”
“Lead time from China that beats most UK distributors. We got dimensional drawings with the order confirmation, which let us prep the crane before the parts even arrived. That’s proper B2B service.”
“Ordered a custom stroke length — they came back with a drawing for approval within 48 hours and delivered to spec. The chrome finish on the rod is noticeably better than what came off our original crane. Very impressed.”
Manufacturing & Custom Engineering Capability
Our hydraulic cylinder manufacturing facility operates CNC turning centres, deep-hole honing machines, and automated chrome-plating lines across a 28,000 m² production floor. This integrated setup means we are not a trading company sourcing from multiple subcontractors — every cylinder passes through a single controlled production chain, from raw tube stock to finished, serialised unit.
Custom engineering is a core capability, not a premium add-on. If your truck crane requires a bore diameter other than Φ70, a rod diameter other than Φ50, or a stroke that differs from 1237 mm, our engineering team can produce a revised drawing within 48 hours of receiving your OEM dimensions. Port orientation, end fitting type (clevis, flange, trunnion), cushioning, and surface treatment are all configurable without minimum order constraints above five units.
UK buyers are supported by English-language technical sales, export documentation including CE-compliant test reports, and freight options through major forwarding agents with Liverpool, Felixstowe, and Tilbury direct service. We work to Incoterms 2020 — CIF, DAP, or EXW — whatever suits your procurement process.
Frequently Asked Questions
edit by gzl
