Interchangeability of competitor hydraulic cylinders under ISO standards

Why replacement between manufacturers is possible at all

The very purpose of the ISO 6020/2 (tie-rod and flange cylinders, 160 bar, Ø 25–200 mm) and ISO 6022 (heavy series, 250 bar) standards is interchangeability: the envelope dimensions, the mounting connection dimensions and the piston rod threads are all standardised. As the manufacturer Conforti Oleodinamica states: a cylinder to ISO can be replaced by another manufacturer's cylinder to the same standard without touching the machine. This is crucial for managers of mixed machine fleets — you are not tied to a single supplier, and in the event of a breakdown all that matters is who delivers sooner.

Which brands can be replaced

Replacement does not rest on the manufacturer's name, but on conformity with the standard. If the original cylinder meets ISO 6020/2 or ISO 6022, it is dimensionally interchangeable with the corresponding Conforti series — regardless of brand. A number of manufacturers offer cylinders in this version:

• Parker Hannifin — the 2H, 3L, HMI / HMD (ISO 6020/2) and MA3 (ISO 6022) series.
• Bosch Rexroth — CDT3 / CGT3 (ISO 6020/2), CDH2 / CSH2 (ISO 6022).
• Atos, Duplomatic MS, Eaton (Vickers), Contarini Oleodinamica, Hydac, Bucher Hydraulics and other manufacturers — cylinders in a version to ISO 6020/2 / 6022 (verify the specific series from the type plate).

What matters is the type plate and the standard, not the brand. Always verify the specific interchangeability against the parameters (see the table and procedure below); for non-standard versions (proprietary dimensions, special mountings), compare the drawing.

Series conversion table (examples)

The most common replacements on the market — Parker and Bosch Rexroth. The same principle (conformity per ISO) applies to the other brands above as well.

Watch out for false equivalents:

• The Parker MMB is a round-line cylinder per ISO 6020/1 (and CETOP RP58H) — a different standard, dimensionally NOT interchangeable with ISO 6020/2.
• The Rexroth CDH1 has main dimensions per DIN ISO 3320 (a Rexroth standard), not full ISO 6022 mounting — verify the dimensions piece by piece.
• The Rexroth CGT3 (double rod) is not standardised — compare the drawing.
• Non-standard extras (Rexroth MX5 mounting, special ports) require a drawing check.

Step-by-step replacement procedure

1. Read the type plate and order code. From the Parker/Rexroth code you can read off the bore, piston rod diameter, stroke and mounting (e.g. Rexroth CDT3MP5/50/36/300… = Ø50/rod 36/stroke 300/mounting MP5). If the plate is missing, measure the bore, piston rod and stroke to the millimetre and photograph the cylinder in situ — a photo replaces pages of specifications.
2. Determine the mounting from the ISO code. Mountings (MF3/MF4 flanges, MS2 foot mounts, MT4 intermediate trunnions, MP3/MP5 rod eyes…) are standardised across manufacturers — with Conforti, for example, the MT4 intermediate trunnion corresponds to mounting H. The configurator offers the correct counterpart for every ISO 6020/2 and ISO 6022 variant.
3. Compare the functional parameters. Operating and peak pressure, cushioning (V/Z/K at Conforti), bleeding (SV/SZ/SK), seal type by medium and temperature (S/L/H/G), port position and thread (ISO 1179-1 / SAE).
4. Verify the dimensions on the 3D model — straight away. In the configurator you build the exact configuration and download the 2D/3D CAD model and datasheet within minutes, without waiting for a quote. You drop the model into your assembly and confirm the dimensional match before ordering.
5. Submit an inquiry with an unambiguous code. The output of the configuration is a unique order code (e.g. CD 50/28 E 300 S) that eliminates communication errors. Send it via the inquiry form — standard delivery within 14 days, urgent production from 48 working hours.

A real-world example: verifying the configuration before ordering

An engineering customer from the Czech Republic inquired about a cylinder with the code CD 200/110 D 1100 SJ 50 S — bore Ø 200 mm, piston rod Ø 110 mm, spherical rod eye (mounting D), stroke 1,100 mm, spacer SJ 50, high-seal seals S. This exact type of inquiry shows what the technical verification involves:

• Series assignment: Ø 200 mm falls within the 125–200 mm bore band — we verified the correct assignment within the tie-rod series (CD 25–100 / DK 125–200) so that the heads, bushings and parts all fit.
• Buckling: a 1,100 mm stroke combined with a rod eye means the least favourable buckling case — before confirmation, a buckling check was carried out per the catalogue procedure (mounting factor by mounting type; the spacer length is added to the stroke for the calculation).
• Spacer: SJ 50 corresponds to the catalogue stroke band of 1,000–1,500 mm — it reduces the load on the guide at long strokes.
• Seals: the S version is available for bores of 125–200 mm.

The result: a confirmed, manufacturable configuration with no hidden risks — even before the price quote. We apply the same process to every replacement of another manufacturer's cylinder.

Why a replacement with Conforti pays off

1) Lead times that keep production running. Conforti can compress the actual manufacture of a custom cylinder to 48 working hours including the final test — the whole process from breakdown to restart can be managed within a matter of days. A "made-to-measure" cylinder (stroke accurate to the millimetre) is not a surcharged special, but the normal mode of one-off production.

2) 3D models instantly, not after registration and approval. The CAD configurator generates 2D/3D models and a complete datasheet on demand, with ongoing feasibility checking. An engineer can verify the installation the same day.

3) A 100% test of every piece per ISO 10100. Not a random batch check: every cylinder undergoes a pressure test at 1.5 times the operating pressure (CD/DK 240 bar, HD/HK 315 bar, DP 375 bar) with systematic recording of the results — traceable even years later.

4) One-off production = an exact replacement. Stroke, piston rod, seals, cushioning, sensors, surface treatments (stainless-steel RRX piston rod, NK nickel plating, RM metal scraper) — all within the ISO building-block system, with no surcharge for a "special".

5) Spare parts available forever. Thanks to ISO dimensions and modular construction, for maintenance and servicing we supply seal sets as well as individual cylinder components — KIT components, front flanges, piston rods, pistons and more — as a spare part; see spare parts and accessories.

6) Local support in your language. Authorised distributor for the Czech Republic/Slovakia: technical consultation, specification translation, delivery across the EU. +420 702 171 872, poptavky@hydraulika.store.

What to watch out for during replacement

• Maximum pressure of the version: "up to 210 bar" applies with the Parker HMI only for certain rod-and-thread combinations. At Conforti, 210 bar is the domain of the HD / HK series — CD / DK stays at 160 bar. Always verify for the specific configuration.
• Stroke tolerance: ISO 8131 prescribes 0/+2 mm; if the original machine relies on a precise end stop, address it with an external stop, not the cylinder tolerance.
• Sensors and electronics: magnetic sensors and position measurement are not part of the standard — compare the connectors and signals (e.g. IO-Link on newer series) separately.
• Bores out of range: the Rexroth CDH2 goes up to Ø 320 mm; the Conforti DP tops out at Ø 200 mm — above that it becomes a special version (SX) on inquiry.