All the dimensions are in millimeters
| Coll.Height A (mm) | Ext. Height B (mm) | Outside Dia. D (mm) | Cyl. Bore Dia. E (mm) | Plunger Dia. F(mm) | Cyl. Base to Advance Port H (mm) | Saddle Dia.J (mm) | Saddle Protrusion from Plunger K (mm) | Plunger Internal Thread O | Plunger Thread Length P (mm) |
| 55 | 63 | 69 | 54.1 | 35.1 | 9 | – | – | ¾” – 16 un | 16 |
| 120 | 162 | 69 | 54.1 | 35.1 | 25 | – | – | – | – |
| 120 | 162 | 69 | 54.1 | 35.1 | 25 | – | – | ¾” – 16 un | 16 |
| 184 | 260 | 69 | 54.1 | 35.1 | 25 | – | – | – | – |
| 162 | 211 | 98 | 73.1 | 54.1 | 19 | 54 | 9.7 | 1-9 /16″ -16 un | 19 |
| 306 | 461 | 98 | 73.1 | 54.1 | 25 | 54 | 9.7 | 1-9 /16″ -16 un | 19 |
| 178 | 242 | 114 | 88.9 | 63.5 | 21 | 63 | 9.00 | 1-13/16″ -16 un | 22 |
| 330 | 485 | 114 | 88.9 | 63.5 | 25 | 63 | 9.00 | 1-13/16″ -16 un | 22 |
| 247 | 323 | 159 | 123.9 | 91.9 | 31 | 91 | 9.00 | 2¾” -16 un | 19 |
| 323 | 476 | 159 | 123.9 | 91.9 | 31 | 91 | 12.00 | 2¾” -16 un | 19 |
| 254 | 330 | 212 | 165.1 | 127.00 | 38 | 126 | 12.00 | 4″ – 16 un | 25 |
| Collar Thread W | Collar Thread Length X (mm) | Center Hole Dia.Y (mm) | Weight (Kg) |
| 2¾” – 16 | 30 | 19.6 | 1.5 |
| 2¾” – 16 | 30 | 19.6 | 2.8 |
| 2¾” – 16 | 30 | 19.6 | 2.8 |
| 2¾” – 16 | 30 | 19.6 | 4.4 |
| 3-7 /8″ – 12 | 38 | 26.9 | 7.7 |
| 3-7 /8″ – 12 | 38 | 26.9 | 14.1 |
| 4½” – 12 | 42 | 33.3 | 10.9 |
| 4½” – 12 | 42 | 33.3 | 21.8 |
| 6¼” – 12 | 48 | 53.8 | 28.1 |
| 6¼” – 12 | 48 | 53.8 | 35.4 |
| 8-3 /8″ – 12 | 60 | 79 | 63 |
We specialize in the manufacture of hollow hydraulic cylinders, also known by various names such as hollow plunger cylinder, center-hole cylinder, hollow piston cylinder, hollow ram cylinder, and hollow ram jack. These cylinders are engineered to provide superior strength, high tonnage capability, and reduced weight, making them ideal for applications requiring powerful linear force with enhanced efficiency and ease of handling.
Features of Hollow Hydraulic Cylinders
- Hollow Rod Design
The hallmark of these cylinders is the hollow piston rod or ram, which significantly reduces overall weight without compromising strength or performance. This design supports internal oil flow and enables specialty applications such as hydraulic jacks or presses requiring hollow center bores. - High Load Capacity and Structural Efficiency
Despite reduced weight, hollow cylinders maintain high resistance to bending and fatigue, providing powerful and reliable force. Their hollow structure also reduces inertia, improving dynamic response and enabling quicker, smoother operation. - Versatility and Application Range
They are widely used in heavy machinery, industrial presses, aerospace testing, construction, mining, and rigging operations requiring compact, robust cylinders with through-center bores.
Manufacturing Process Overview
- Material Selection and Tube Preparation
Seamless steel tubes, often cold-drawn for toughness and fatigue resistance, are precision cut and internally honed for optimal surface finish to reduce friction and wear. - Rod and Piston Fabrication
The hollow piston rod and piston are CNC machined to precise tolerances. A hole is drilled through the center of the piston rod, and grooves are machined inside for sealing and mounting the piston. Rod heads and ends are carefully welded and aligned to achieve coaxiality and perfect sealing. - Assembly and Welding
Components such as the rod head, shaft, and rod end are assembled and welded with strict quality control. Specialized welding and finishing techniques ensure strength and leak-tightness. - Surface Treatments
Hard chrome plating or polishing is applied to critical sliding surfaces to provide corrosion resistance, minimize wear, and extend cylinder life. - Testing and Quality Assurance
Finished cylinders undergo rigorously controlled dimensional inspections, hydraulic pressure tests, leak testing, and cycle durability checks to verify functionality under high pressure and long service cycles.
Advantages of Choosing Our Hollow Hydraulic Cylinders
- Precise CNC machining combined with stringent quality controls ensures durability and reliability.
- Customizable configurations for stroke length, bore size, pressure rating, and mounting options tailored to your specific industrial needs.
- Advanced manufacturing techniques optimize hollow rod design for maximum strength with minimized weight.
- Comprehensive after-sales support and timely delivery to meet your project schedules.
Contact us to discuss your requirements for hollow hydraulic cylinders, and let our expert team provide a tailored, high-performance hydraulic solution suited for your demanding industrial applications.