What is the difference between the HD / HK and DP series?

HD and HK are flange-mounted cylinders to ISO 6020/2 with a 210 bar operating pressure; HD covers bores of 50–100 mm, HK continues from 125 to 200 mm. The DP series is designed to ISO 6022 for 250 bar and uses thicker rods for the same bore — so it offers better resistance to buckling and side loads on long strokes.

What operating pressure do heavy-duty cylinders handle?

Flange-mounted HD and HK cylinders are rated for a continuous operating pressure of 210 bar. The heavy-duty DP series to ISO 6022 works up to 250 bar, which makes it ideal for rolling mills, forming machines and heavy presses with high forces.

Which applications are these cylinders suited to?

Typically rolling mills, forming machines, heavy presses, hydraulic lifts and robust industrial mechanisms where high force, structural stiffness and a long service life under demanding operation are decisive.

Why does the DP series have thicker rods than HD / HK?

For the same bore, DP offers larger rod diameters — for example with a 100 mm bore the rods are 63 or 70 mm. A thicker rod increases resistance to buckling and side loads, which is advantageous on long strokes and applications with a higher working pressure.

Is there a minimum stroke on the DP series?

A minimum stroke on DP applies only to the H mounting (centre trunnions ISO MT4) — for example with a 100 mm bore it is 145 mm, and with 125 mm it is 175 mm. The other DP mountings have no minimum stroke. On the HD / HK series a minimum stroke applies to all mountings according to bore (Ø 100 mm = 115 mm).

Which seals are available for heavy duty?

Four configurations are available: S (high seal up to 0.5 m/s), L (low-friction PTFE up to 1 m/s), H (Viton for oil temperatures up to +150 °C, typical for rolling mills) and G (PTFE CG for HFC fluids). A metal scraper ring can be added for contaminated environments.

Can the cylinders be supplied with end-of-stroke cushioning?

Yes. Hydraulic cushioning is particularly important on heavy cylinders — variant K cushions at both ends, V cushions on extension only and Z on retraction only. Cushioning protects the structure from impacts on deceleration and is recommended for rolling mills and heavy-duty operation.

How to handle long strokes over 1000 mm?

For long strokes a spacer is fitted to extend the base length of the cylinder. On HD / HK a spacer is used from 1000 mm, and on the more robust DP series from 1500 mm. HD / HK handle strokes up to 4000 mm, and the DP series up to 6000 mm.

When to choose a TP servo cylinder with position measurement?

If the application requires precise continuous measurement and control of the rod position — for example synchronised movements or accurate closed-loop positioning — the TP servo solution with integrated position feedback is the right choice.

Hydraulic cylinders for rolling mills, forming machines and heavy dutyHD / HK (ISO 6020/2) · DP (ISO 6022) · TP servo

For rolling mills, forming machines, heavy presses and heavy-duty applications, the most common choice is double-acting flange-mounted HD / HK cylinders to ISO 6020/2 (210 bar, Ø 50–200 mm) and the heavy-duty DP series to ISO 6022 (250 bar, Ø 50–200 mm incl. Ø 140 mm). DP has thicker rods for the same bore — higher buckling resistance on long strokes. Where precise continuous position control is required, the TP servo series is used. Supplied by hydraulika.store, an authorised distributor of Conforti Oleodinamica for the Czech Republic, Slovakia and the EU — with an online configurator, free CAD models and delivery within 14 working days.

250 barDP · ISO 6022

210 barHD / HK · ISO 6020/2

Ø 50–200 mmBore

up to 6000 mmMaximum stroke (DP)

Configure a cylinder CAD 3D models

HD / HK datasheet (PDF) DP datasheet (PDF)

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DP · ISO 6022 · 250 bar

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HD / HK · ISO 6020/2 · 210 bar

ISO 6022 ISO 6020/2 Heavy-duty 210 / 250 bar

Need precise position measurement? For synchronised movements and precise continuous control of the rod position, the TP servo series with integrated feedback is the answer. Suited to cases where simple end-position sensing is not enough and closed-loop travel control is required. More about TP servo cylinders →

Standard industrial motion is enough for you? For lower pressures and everyday applications (automotive, automation, clamping) the tie-rod CD / DK cylinders to ISO 6020/2 are a better fit — 160 bar, Ø 25–200 mm. Cheaper and more compact than the flange-mounted HD / HK. View CD / DK / MD cylinders →

Frequently Asked Questions

FAQ — HD / HK and DP cylinders

Tap a question — the answer appears below. Verified against the Conforti Oleodinamica technical documentation.

Useful articles from our Technical Centre: Interchangeability of competitor cylinders to ISO → Modular vs. welded hydraulic cylinders → Cylinder assembly, maintenance and service — Conforti KIT → All articles in the Technical Centre →

Online configurator

Configure your hydraulic cylinder online

Choose the series, mounting, bore and stroke in the online configurator. It builds the exact cylinder, generates the configuration code (SKU) and a technical datasheet, and lets you download the CAD model.

Configurator not loading? Open the configurator in a new tab →

Technical specifications

HD / HK and DP technical specifications

Flange-mounted HD / HK cylinders to ISO 6020/2 and the heavy-duty DP series to ISO 6022. A robust design for high forces, a long service life and reliability in demanding operation.

Standard

HD / HK: ISO 6020/2 · DP: ISO 6022

Flange-mounted (HD/HK) and heavy-duty (DP) design

Operating pressure

HD / HK: 210 bar · DP: 250 bar

Tested to ISO 10100

Bore

HD: Ø 50–100 mm · HK: Ø 125–200 mm

DP: Ø 50–200 mm (incl. Ø 140 mm)

Maximum stroke

HD / HK: up to 4000 mm · DP: up to 6000 mm

Spacer for long strokes (DP from 1500 mm)

Rod

DP has thicker rods than HD / HK

Higher resistance to buckling and side loads

Seals

S · L (PTFE) · H (Viton) · G (HFC)

H for oil temperatures up to +150 °C (rolling mills)

Three solutions for heavy duty

When to choose HD / HK, DP or TP servo?

Flange-mounted HD / HK cylinders (ISO 6020/2, 210 bar) cover more demanding industrial applications and presses. The heavy-duty DP (ISO 6022, 250 bar) has thicker rods for rolling mills, forming machines and the highest loads. TP servo serves precise continuous measurement and control of the rod position.

HD / HK seriesISO 6020/2 Flange-mounted · 210 bar · Ø 50–200 mm · stroke up to 4000 mm. Presses, higher pressures, robust mechanisms, long strokes. HD / HK series detail → DP seriesISO 6022 Heavy-duty · 250 bar · Ø 50–200 mm incl. Ø 140 · thicker rods. Rolling mills, forming machines, heavy presses. DP series detail → TP servoPositioning Precise continuous measurement and control of the rod position. Synchronised movements, closed-loop travel control. TP servo cylinders detail →

Line automation Press auxiliary motions Sheet metal forming Load handling Lifting mechanisms Tilters and positioning

Industrial applications

Where hydraulic cylinders are used in forming machines and presses

Rolling mills, forming machines, heavy presses, hydraulic lifts and robust industrial mechanisms — wherever high force, structural stiffness and a long service life are decisive. From flange-mounted ISO 6020/2 series (HD / HK) through heavy-duty ISO 6022 (DP) to the TP servo solution for precise positioning. For standard motion and limited space, the tie-rod CD / DK and compact RP / MP / RQ series follow on.

Need help choosing a cylinder for your application?

CAD & technical documentation

CAD models and 2D drawings of HD / HK and DP cylinders

Download the 3D model or 2D drawing for your exact cylinder configuration. The model matches the bore, rod, mounting and stroke from the configurator. STEP, IGES, Parasolid, STL, DWG, DXF and PDF formats, free of charge.

How to get a 3D model or drawing of an HD / HK / DP cylinder

1
Configure the cylinder — choose the series, bore, rod, mounting and stroke in the configurator above
2
Open the 2D / 3D model section — after adding the product to your request the configuration code (SKU) is shown
3
Enter the configuration code (SKU) — paste the cylinder code into the "CODE WIZARD" and confirm the configuration
4
Choose a format and download — STEP, IGES, Parasolid, DWG, DXF and more

Available formats:

STEPIGESParasolidSTLDWGDXFPDF

CAD models and technical documentation by series

3D models and drawings HD / HKISO 6020/2 flanges · STEP, IGES, DWG, DXF, PDF

3D models and drawings DPISO 6022 heavy-duty 250 bar · stroke up to 6000 mm

3D models and drawings TP servoISO 6022 servo · precise position measurement

Position sensing

Position sensing options for hydraulic cylinders

End positions

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SPV / SPZ / SPK proximity switches →

Full stroke

Servo cylinders TP →

For a comparison of all position-sensing methods, technical parameters and selection guidance, see Position sensors for hydraulic cylinders →

Brand authority

Why Conforti through hydraulika.store

We are an authorised distributor of the Italian manufacturer Conforti Oleodinamica. For rolling mills and forming machines we supply HD / HK and DP cylinders for high and cyclic loads — a high-pressure design with the full manufacturer's warranty. Authorised supply with technical support.

Authorised distributor

Genuine Conforti cylinders with the full manufacturer's warranty. No re-exports or aftermarket parts. Direct distribution agreement.

High-pressure cylinders for forming

The HD / HK and DP series for high operating pressures and the repeated loads of forming machines and rolling mills.

ISO 9001 since 2008

Conforti has held an ISO 9001 certified quality management system for 18+ years. Periodically validated business processes.

Strong DP rods

The DP series has thicker rods than HD / HK — higher resistance to buckling and radial loads in forming applications.

100% individual testing

Every cylinder undergoes an individual test protocol to ISO 10100 before delivery. Records kept on file.

Parker / Bosch replacement

Cylinders fully compatible with Parker Hannifin, Bosch Rexroth and other makers to ISO standards — without modifying the equipment.

Made in Italy

Manufactured in Monza (Lombardy). Proven design to ISO 6020/2 and ISO 6022, DIN 24554 / 24333.

Service and spare parts

As an official distributor we provide direct access to seals, guides and spare parts with a compatibility guarantee.

If you have any questions, please contact us — Adam Tomášek, sales & technical representative and authorized distributor of Italian Conforti Oleodinamica hydraulic cylinders for CZ, SK and the EU since 2023, who prepared this content for you. Contact →