A Customer Case: Why Force, Pressure, Stroke, Speed and Cycle Frequency Must Be Evaluated Together

Selecting a hydraulic cylinder for a demanding application cannot be based on force alone.

When a Customer requires 500 kN of force, a 200 mm stroke, a hydraulic pressure limited to 50 bar, and a very high 10 Hz cycle frequency, the challenge is no longer simply choosing a cylinder with a sufficiently large bore.

The entire hydraulic system must be evaluated:

• required force;
• operating pressure;
• cylinder bore;
• rod diameter;
• stroke;
• movement speed;
• cycle frequency;
• pump flow;
• available installation space.

A technical request received by the Vega Team illustrates this very clearly. The Customer was looking for a V215CR ISO 6020/2 hydraulic-cylinder solution capable of dealing with a required force of 500 kN in both extension and retraction, while the available pump could operate at a maximum pressure of only 50 bar.

The analysis showed that the force requirement alone already demanded a very large hydraulic solution. But the most restrictive parameter was actually the requested 10 Hz cycle frequency combined with a 200 mm stroke.

This case demonstrates why hydraulic-cylinder sizing must always consider the complete operating cycle rather than a single parameter.

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1. The Customer’s Requirement

The technical request involved several demanding requirements.

The Customer needed:

• approximately 500 kN of force in extension;
• approximately 500 kN of force in retraction;
• a 200 mm stroke;
• a very high 10 Hz cycle frequency;
• a hydraulic system operating at only 50 bar.

The requested cylinder family was the V215CR, manufactured according to ISO 6020/2.

This combination immediately creates an engineering challenge.

A force of 500 kN is substantial.

A 200 mm stroke is also considerable.

But combining 200 mm of movement with a 10 Hz cycle frequency creates a completely different level of hydraulic demand.

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2. The First Question: How Much Cylinder Area Is Required?

The fundamental hydraulic equation is:

F = P × A

where:

• F = hydraulic force;
• P = hydraulic pressure;
• A = effective piston area.

If the required force is:

500 kN

and the available pressure is only:

50 bar

the required piston area becomes very large.

Converting the force:

500 kN ≈ 50,986 kgf

At 50 bar:

A = 50,986 / 50

A ≈ 1,020 cm²

This is an extremely large effective piston area.

This explains why the Vega Team immediately identified the need for a very large cylinder or multiple cylinders when considering the 500 kN requirement.

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3. Why 50 bar Changes Everything

Hydraulic cylinders can generate very high forces, but the required piston diameter depends directly on the available pressure.

For a given force:

lower pressure → larger piston area

higher pressure → smaller piston area

This is why the available pump pressure is one of the first parameters that must be established when sizing a cylinder.

In this case, the pump could provide only 50 bar, which significantly increased the required cylinder size.

Had the system been able to operate at a substantially higher pressure, the required piston area could have been reduced.

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4. One Very Large Cylinder or Two Smaller Cylinders?

The Vega Team identified two possible approaches for achieving approximately 500 kN:

Option 1

Use a cylinder with an alesaggio greater than 200 mm.

Option 2

Use two cylinders with Ø160 mm bore, operating at 160 bar.

This is an important engineering consideration.

A single very large cylinder is not necessarily the only solution.

Multiple cylinders can sometimes provide the required total force while offering greater flexibility in the mechanical installation.

However, multiple-cylinder solutions introduce their own design considerations, including:

• synchronization;
• load distribution;
• hydraulic circuit design;
• mechanical alignment;
• installation space.

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5. Why Ø160 mm at 160 bar Can Generate a Very Large Force

A Ø160 mm piston has an area of approximately:

A = π × 160² / 4

A ≈ 20,106 mm²

or:

≈ 201.1 cm²

At:

160 bar

the theoretical extension force is approximately:

F = 160 × 201.1

F ≈ 32,176 kgf

Two cylinders would therefore theoretically provide approximately:

64,352 kgf

or roughly:

631 kN

on the extension side.

This gives a reasonable margin over the required 500 kN.

The Vega communication specifically identified two Ø160 mm cylinders at 160 bar as an alternative to a single cylinder larger than 200 mm.

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6. Why Retraction Force Is Different

A double-acting hydraulic cylinder does not necessarily generate the same force in extension and retraction.

The reason is the rod.

During extension, hydraulic pressure acts over approximately the entire piston area.

During retraction, the rod occupies part of that area.

Therefore:

Extension force = pressure × full piston area

while:

Retraction force = pressure × (piston area − rod area)

This difference becomes particularly important when the Customer requires nearly the same force in both directions.

In the specific configuration evaluated by Vega at 50 bar, the proposed cylinder could generate approximately:

10,000 kgf in extension

and:

8,125 kgf in retraction.

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7. The Specific V215CR Configuration Evaluated

The Vega Team calculated the performance of the CR160070C0GHAN200 configuration using the Customer’s available 50 bar pressure.

The resulting approximate forces were:

These values were explicitly provided by the Vega Team in the technical correspondence.

This calculation immediately shows that a single Ø160 mm cylinder at 50 bar would be far below the 500 kN requirement.

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8. How Many 160 mm Cylinders Would Be Required at 50 bar?

If one cylinder produces approximately:

10,000 kgf

in extension at 50 bar, then reaching approximately:

50,986 kgf

would theoretically require more than five cylinders.

This illustrates the enormous effect of operating pressure.

At 50 bar, the hydraulic system requires a very large piston area.

At 160 bar, the same piston area produces more than three times the force.

This is why pressure selection and cylinder sizing cannot be considered separately.

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9. The Most Restrictive Requirement Was Not Actually the Force

The force requirement was demanding, but the Vega Team identified another major problem:

10 Hz cycle frequency with a 200 mm stroke.

The technical response explained that a 10 Hz cycle frequency could potentially be achieved with a stroke of approximately 8–10 mm, but not with a 200 mm stroke.

This is the key lesson of the case.

A cylinder can have enough force and still be completely unsuitable because it cannot move the required distance quickly enough.

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10. What Does 10 Hz Actually Mean?

A frequency of:

10 Hz

means:

10 cycles per second

Therefore, the complete cycle time is:

1 / 10 = 0.1 seconds

That is only:

100 milliseconds per cycle.

If the cylinder must move 200 mm during a single movement, the required velocity becomes extremely high.

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11. 200 mm Stroke at 10 Hz

If the cylinder were expected to complete a 200 mm movement in 0.1 seconds:

v = s / t

v = 0.2 / 0.1

v = 2 m/s

This is already far above the 0.1 m/s recommended speed mentioned by the Vega Team for this type of application.

And this calculation assumes that the entire 0.1 seconds can be dedicated to the 200 mm movement.

If the cycle includes:

• acceleration;
• deceleration;
• dwell time;
• return movement;

the actual required peak velocity would be even higher.

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12. Why 8–10 mm Is More Compatible With 10 Hz

The Vega Team indicated that a 10 Hz frequency could potentially be achieved with a stroke of approximately:

8–10 mm.

At 10 mm per cycle and 10 cycles per second:

10 mm × 10 = 100 mm/s

or:

0.1 m/s

This corresponds directly to the recommended movement speed identified by Vega.

This is a very useful engineering observation.

A short stroke can be compatible with a high cycle frequency.

A long stroke dramatically increases the required velocity and hydraulic flow.

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13. The Relationship Between Stroke, Frequency and Speed

The basic relationship is:

v = s × f

where:

• v = average linear velocity;
• s = stroke per cycle;
• f = cycle frequency.

For:

10 mm × 10 Hz

we obtain:

100 mm/s = 0.1 m/s

For:

200 mm × 10 Hz

we obtain:

2,000 mm/s = 2 m/s

The difference is enormous.

This is why the Vega Team considered the requested combination of 200 mm stroke and 10 Hz frequency highly restrictive.

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14. Speed Is Directly Related to Pump Flow

Cylinder speed is determined by hydraulic flow.

The basic relationship is:

Q = A × v

where:

• Q = hydraulic flow;
• A = piston area;
• v = cylinder velocity.

Therefore, a large cylinder moving at high speed requires an enormous hydraulic flow.

This creates another problem with the Customer’s application.

The larger the cylinder required to achieve 500 kN at low pressure, the greater the flow requirement becomes when the cylinder must move quickly.

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15. Why Large Force and High Speed Are Difficult to Combine

This case combines two demanding requirements:

Very high force

Approximately:

500 kN

Very high movement frequency

10 Hz

These requirements work against each other from a hydraulic-system perspective.

To generate high force at low pressure, a large piston is required.

But a large piston requires a large oil volume to move through a given stroke.

If the stroke is long and the frequency is high, the required flow becomes extremely large.

Therefore:

large bore + long stroke + high frequency = very high pump flow requirement

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16. The Pump Becomes a Critical Component

This is why the Vega Team stated that the actual pump flow needed to be determined before finalizing the recommended speed.

The cylinder cannot be selected independently from the pump.

The hydraulic system must be capable of supplying the required volume of oil at the required pressure and frequency.

The designer therefore needs to know:

• maximum pump pressure;
• available flow;
• pressure-flow characteristics;
• valve capacity;
• accumulator availability, if applicable;
• hydraulic line dimensions.

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17. The Importance of Valve Flow Capacity

Even if the pump can provide the required flow, the valves and hydraulic lines must also be capable of delivering it.

A high-speed hydraulic cylinder requires sufficient flow through:

• control valves;
• hoses;
• fittings;
• manifolds;
• ports.

Pressure losses can increase as flow increases.

Therefore, a theoretical cylinder calculation is only the beginning of the engineering process.

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18. Why the 0.1 m/s Speed Recommendation Matters

The Vega Team indicated a recommended speed of approximately:

0.1 m/s

for this type of cylinder.

At that speed, a 200 mm stroke requires:

t = s / v

t = 0.2 / 0.1

t = 2 seconds

for one complete 200 mm movement in one direction.

This is fundamentally incompatible with a 10 Hz cycle if the 200 mm movement itself must be completed within each cycle.

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19. A Simple Comparison

This table illustrates why the requested combination becomes increasingly difficult as stroke increases.

The Vega Team therefore suggested that the 10 Hz frequency could be approached with approximately 8–10 mm stroke, rather than 200 mm.

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20. Force Is Not the Only Selection Criterion

This case provides an excellent reminder that selecting a hydraulic cylinder requires at least four fundamental checks:

1. Force

Can the cylinder generate the required force?

2. Stroke

Can it provide the required displacement?

3. Speed

Can it move at the required velocity?

4. Frequency

Can it repeat the movement at the required cycle rate?

A cylinder that satisfies only the first requirement is not necessarily suitable.

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21. The V215CR Platform

The V215CR is a double-acting tie-rod hydraulic-cylinder series manufactured according to UNI ISO 6020/2 dimensions.

The official Vega documentation states that the standard range includes piston bores from 25 to 200 mm and strokes from 1 to 1,500 mm. (vegacylinders.com)

The V215CR can be used for linear movements in applications such as carts, pins and plugs in injection molds. It can also be customized for special applications.

The range is therefore broad enough to cover very different force and stroke requirements.

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22. Pressure Capability of the V215CR

The official V215CR documentation specifies a maximum working pressure of 215 bar and a maximum speed of 1 m/s. (vegacylinders.com)

This is an important distinction.

The Customer’s available pump pressure was only:

50 bar

Therefore, although the cylinder itself may be designed for substantially higher pressure, the actual application is limited by the hydraulic system available to the Customer.

The cylinder’s maximum pressure is not the same thing as the system’s operating pressure.

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23. The Cylinder Cannot Compensate for an Undersized Pump

Suppose a cylinder is capable of operating at 215 bar.

If the actual pump can provide only 50 bar, the cylinder cannot magically generate the force associated with 215 bar.

The available force is determined by the actual operating pressure:

F = P × A

This is why the Vega Team recalculated the performance of the Ø160 mm cylinder using the Customer’s actual 50 bar pressure.

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24. The Importance of the Rod Diameter

The selected V215CR configuration had:

Ø160 mm bore

and:

Ø70 mm rod.

The rod diameter affects the available retraction area.

The piston area is approximately:

201.1 cm²

The rod area is approximately:

38.5 cm²

Therefore, the effective retraction area is approximately:

201.1 − 38.5 = 162.6 cm²

At 50 bar:

162.6 × 50 ≈ 8,130 kgf

This closely corresponds to the approximately 8,125 kgf retraction force stated by the Vega Team.

This provides a clear example of why extension and retraction forces must be calculated separately.

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25. Why the Customer’s 500 kN Requirement Was So Demanding

The requested force was approximately:

500 kN ≈ 50,986 kgf

while the analyzed Ø160 mm cylinder at 50 bar produced only approximately:

10,000 kgf extension

and:

8,125 kgf retraction.

Therefore, the application required a substantially larger total effective piston area than one Ø160 mm cylinder could provide at 50 bar.

This explains Vega’s initial alternatives:

• one cylinder larger than 200 mm bore;
• or two Ø160 mm cylinders at 160 bar.

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26. Two Cylinders Can Solve a Force Problem, but Not Necessarily a Speed Problem

This is another important lesson.

Increasing the number of cylinders can increase total available force.

But it does not automatically solve the problem of:

200 mm stroke at 10 Hz.

If two cylinders need to move 200 mm ten times per second, the hydraulic system still has to supply the necessary oil volume at the required speed.

In other words:

more cylinders solve force

but they do not automatically solve:

frequency + stroke + flow.

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27. Force and Flow Must Be Evaluated Together

For a large hydraulic cylinder:

Force depends mainly on pressure × area

while:

speed depends mainly on flow ÷ area.

This produces an important engineering relationship.

Increasing the cylinder diameter:

• increases force at a given pressure;
• but also increases the oil volume required for a given speed.

Therefore, selecting a larger cylinder to solve a force problem can make a high-speed application even more demanding from the hydraulic-flow perspective.

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28. What Should Be Changed if 10 Hz Is Mandatory?

If 10 Hz is an absolutely fixed requirement, the engineering solution may need to reconsider the movement itself.

Possible design questions include:

• Is the entire 200 mm stroke really required in every cycle?
• Can the effective stroke be reduced?
• Can the movement be divided into stages?
• Can the mechanical mechanism amplify a shorter hydraulic stroke?
• Is an accumulator required?
• Can the hydraulic circuit provide the required instantaneous flow?
• Is another actuation technology more appropriate?

The source document itself does not propose these alternatives, so they should be treated as general engineering considerations, not as recommendations made by Vega in this specific case.

The documented Vega recommendation was that 10 Hz could potentially be achieved with approximately 8–10 mm stroke, rather than 200 mm.

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29. The Real Bottleneck: The Combination of Parameters

The Customer’s request demonstrates that engineering limitations often arise from the combination of parameters.

Individually:

500 kN

may be achievable.

200 mm stroke

may be achievable.

10 Hz

may be achievable for a very short stroke.

But:

500 kN + 200 mm + 10 Hz + 50 bar

creates a much more demanding system.

This is why the complete application must be analyzed before selecting the cylinder.

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30. A Practical Cylinder-Sizing Workflow

For demanding applications, the following sequence is useful.

Step 1 — Define the required force

Determine both:

• extension force;
• retraction force.

Step 2 — Define the operating pressure

Use the actual pressure available from the pump.

Step 3 — Calculate the required piston area

Use:

A = F / P

Step 4 — Select a preliminary bore

Compare the required area with available cylinder sizes.

Step 5 — Verify the rod diameter

Calculate the effective retraction area.

Step 6 — Define the stroke

Determine the actual displacement required.

Step 7 — Define the required frequency

Calculate the movement speed:

v = s × f

Step 8 — Calculate hydraulic flow

Use:

Q = A × v

Step 9 — Verify pump and valve capacity

Check that the hydraulic system can supply the required flow.

Step 10 — Verify mechanical installation

Check space, mounting, alignment and load conditions.

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31. Why the Pump Specification Was Still Required

The Vega Team specifically stated that the recommended speed was approximately 0.1 m/s, but that it was necessary to establish the flow capacity of the Customer’s existing pump.

This is a critical point.

A cylinder’s theoretical maximum speed does not tell us whether the Customer’s hydraulic system can actually achieve it.

The final operating speed depends on the available flow.

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32. A 200 mm Stroke at 0.1 m/s

At the recommended speed of:

0.1 m/s

a 200 mm stroke takes:

2 seconds

for one direction.

Therefore:

• extension ≈ 2 seconds;
• retraction ≈ 2 seconds.

Even without accounting for acceleration, deceleration or dwell time, a complete out-and-back movement would already require approximately:

4 seconds.

This is obviously very far from a 10 Hz cycle.

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33. A 10 mm Stroke at 0.1 m/s

By comparison:

10 mm / 0.1 m/s = 0.1 seconds

This corresponds to:

10 movements per second

under the simplified assumption of one 10 mm movement per 0.1-second cycle.

This explains the Vega Team’s statement that a 10 Hz frequency could be achieved with a stroke of approximately 8–10 mm.

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34. The Case Shows Why “Maximum Speed” Is Not Enough

Even when a cylinder datasheet provides a maximum speed, that value should not automatically be interpreted as a sustainable operating speed for every application.

Actual operation depends on:

• flow;
• pressure;
• load;
• acceleration;
• deceleration;
• duty cycle;
• temperature;
• hydraulic circuit;
• valve performance.

The V215CR official page specifies a maximum speed of 1 m/s, but the Vega Team recommended approximately 0.1 m/s for this particular application and requested information about the pump flow.

This distinction is extremely important.

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35. A Cylinder’s Datasheet Does Not Replace Application Engineering

A catalog tells the engineer what a product can potentially do.

Application engineering determines what the product should actually do in a specific machine.

The V215CR can have:

• large bores;
• long strokes;
• high pressure capability;
• high nominal speed.

But the Customer’s application still has to be evaluated according to its own:

force + stroke + pressure + frequency + flow requirements.

The case is a clear example of this difference.

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36. Customer Case Summary

The values in this table are based on the technical correspondence and the calculations directly supported by it.

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37. The Main Engineering Lessons

This Customer case provides several important lessons.

1. Low hydraulic pressure requires large cylinders

At only 50 bar, achieving 500 kN requires a very large effective piston area.

2. Extension and retraction forces are different

The rod reduces the effective area during retraction.

3. Stroke and frequency determine speed

A 200 mm stroke at 10 Hz implies an extremely high theoretical velocity.

4. Speed determines flow

Large cylinders moving rapidly require very high hydraulic flow.

5. The pump must be evaluated together with the cylinder

The available pressure and flow determine what the cylinder can actually achieve.

6. More cylinders solve force, not necessarily speed

Parallel cylinders can increase force, but the hydraulic circuit must still provide the required flow.

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Conclusion

This Customer case demonstrates why selecting a hydraulic cylinder for a demanding application requires much more than calculating the required force.

The initial requirement involved approximately 500 kN in both extension and retraction, a 200 mm stroke, and a 10 Hz cycle frequency, while the available hydraulic system could provide only 50 bar.

At that pressure, the required piston area becomes extremely large. The Vega Team therefore identified two possible approaches for achieving the required force: a cylinder with a bore greater than 200 mm, or two Ø160 mm cylinders operating at 160 bar.

For the analyzed Ø160/70 mm configuration at 50 bar, the calculated forces were approximately 10,000 kgf in extension and 8,125 kgf in retraction.

However, the most restrictive parameter was the combination of 200 mm stroke and 10 Hz frequency.

At 10 Hz, a 200 mm stroke would theoretically require an average velocity of approximately:

2 m/s

while the Vega Team indicated a recommended speed of approximately:

0.1 m/s

and explained that a 10 Hz frequency could potentially be achieved with a stroke of only around 8–10 mm, rather than 200 mm.

The final speed also depends on the available pump flow, which Vega requested before finalizing the hydraulic solution.

The broader engineering lesson is therefore:

A hydraulic cylinder cannot be selected from force alone. Force, pressure, bore, stroke, speed, frequency and hydraulic flow must all be evaluated as one integrated system.

In demanding applications, the correct question is not simply:

“Which cylinder can generate 500 kN?”

It is:

“Which complete hydraulic system can generate 500 kN, move the required stroke, at the required speed and frequency, with the pressure and flow actually available?”

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Useful and Verified URLs

1. V215CR – Tie-Rod Hydraulic Cylinders ISO 6020/2

The official Vega product page for the V215CR. It confirms the ISO 6020/2 design, bore and stroke range, maximum working pressure, maximum speed, construction and customization possibilities.

V215CR – Tie-Rod Hydraulic Cylinders ISO 6020/2

2. V215CR for Cart and Plug Movement

This official Vega category explains the use of V215CR cylinders for moving carts, pins, plugs and other components that can create undercuts in plastic injection molds.

Hydraulic Cylinders for Cart and Plug Movement

3. Hydraulic Cylinders for Molds

The official Vega catalog page covering the hydraulic-cylinder range for plastic injection and die-casting molds. It includes the V215CR and confirms that standard fixing configurations can be customized according to Customer requirements.

Hydraulic Cylinders for Molds

4. Hydraulic Cylinder Catalog

The official Vega catalog groups cylinders according to their application and provides access to the different product families.

Hydraulic Cylinder Catalog – Vega Cylinders

5. Custom Hydraulic Cylinders

This official Vega page explains the company’s ability to develop customized hydraulic cylinders according to specific Customer requirements. It is particularly relevant when the required force, dimensions or operating conditions fall outside a standard configuration.

Custom Hydraulic Cylinders – Vega Cylinders

6. Hydraulic Cylinder Sizing and Force Calculation

An iCVEGA technical article explaining the importance of calculating the real forces acting on hydraulic cylinders rather than selecting a cylinder from bore and stroke alone. It is a useful complementary technical resource for this case.

How to Calculate the Pulling Force of Hydraulic Cylinders in Injection Molds