Hydraulic cylinder rams are critical components in machinery across industries such as construction, mining, agriculture, manufacturing, and marine. They convert hydraulic fluid pressure into linear force, enabling heavy lifting, pushing, and pulling tasks that would be impossible with mechanical power alone.
This guide explores the different sizes of hydraulic cylinder rams, how they are categorised, and their typical applications.
Understanding Hydraulic Cylinder Ram Sizes
Hydraulic rams come in a wide range of sizes to suit specific equipment and operational requirements. Size isn’t just about length, it also involves bore diameter, stroke length, and rod diameter.
1. Bore Diameter
The bore diameter is the inside width of the cylinder barrel. It determines how much fluid can act on the piston, which directly impacts the output force.
- Small bore cylinders (25–50mm) – Used for light-duty tasks where precision and speed matter more than brute force.
- Medium bore cylinders (50–100mm) – A balance between force and speed, suited to general industrial applications.
- Large bore cylinders (100mm+) – Deliver high force, ideal for heavy-duty lifting and pushing.
2. Stroke Length
Stroke length is the distance the ram can extend and retract.
- Short stroke (less than 300mm) – Common in compact machinery with limited space.
- Medium stroke (300mm–1m) – Suitable for general material handling and industrial equipment.
- Long stroke (over 1m) – Used in applications requiring extended reach, such as cranes or long-reach excavators.
3. Rod Diameter
The rod transfers force from the piston to the load. A larger rod diameter increases strength and reduces the risk of bending under load, especially in high-pressure applications.
Common Sizes and Where They’re Used
Small Hydraulic Rams
- Bore size: 25–50mm
- Stroke: up to 500mm
- Uses: Agricultural equipment (harvesters, small tractors), compact loaders, light manufacturing machinery.
Medium Hydraulic Rams
- Bore size: 50–100mm
- Stroke: up to 1m
- Uses: Forklifts, medium-sized excavators, general construction equipment, transport loading ramps.
Large Hydraulic Rams
- Bore size: 100mm+
- Stroke: 1m+
- Uses: Mining haul trucks, marine winches, industrial presses, heavy cranes, bulk handling equipment.
For guidance on choosing the right ram size, see How to Choose the Right Hydraulic Cylinders.
Applications by Industry
Construction
- Lifting booms, controlling excavator arms, compactors, and pile drivers.
Mining
- Dump truck beds, rock crushers, and large-scale earthmoving equipment.
Agriculture
- Front-end loaders, seeders, balers, and irrigation systems.
Manufacturing
- Industrial presses, moulding machines, and assembly line equipment.
Marine
- Winch systems, steering gear, and hatch covers.
Factors to Consider When Selecting a Hydraulic Cylinder Ram
- Operating Pressure – Ensure the cylinder’s rating matches or exceeds system pressure.
- Mounting Style – Clevis, trunnion, or flange mounts affect space and motion requirements.
- Duty Cycle – High-use equipment requires durable seals and coatings.
- Environmental Conditions – Corrosion-resistant materials for marine use; dust seals for mining.
- Maintenance Access – Some cylinder positions are harder to service, so reliability matters.
Why Size Matters in Hydraulic Performance
A cylinder that’s too small won’t provide enough force, while one that’s oversized may be slow and inefficient. Correct sizing improves:
- Force output
- Cycle times
- Energy efficiency
- Component lifespan
For precision sizing and performance optimisation, regular inspection and maintenance are essential. Read our hydraulic system maintenance tips.
Frequently Asked Questions
1. What is the difference between a hydraulic ram and a hydraulic cylinder?
A hydraulic ram is a type of hydraulic cylinder specifically designed for pushing or lifting in one direction. Many people use the terms interchangeably, but technically, a ram usually has a single-acting design.
2. How do I know what size hydraulic ram I need?
Determine the required force, stroke length, and operating pressure. Then match these to bore size, rod size, and stroke capacity. Use manufacturer charts or seek expert guidance.
3. Can a larger hydraulic cylinder increase lifting power?
Yes. A larger bore allows more fluid to act on the piston, increasing force output. However, it may also slow down the extension and retraction speed.
4. What materials are hydraulic rams made from?
Typically high-strength steel, with rods often chrome-plated for wear and corrosion resistance. Special coatings and stainless steel alloys are used for marine or corrosive environments.
5. Are custom-sized hydraulic rams available?
Yes. Many hydraulic service providers can design and manufacture cylinders tailored to specific equipment and operating conditions.
6. How often should hydraulic rams be serviced?
Service intervals depend on usage, environment, and duty cycle. High-use or harsh-condition cylinders may need inspection every few months.