How to Read a Pneumatic Cylinder Model Code (ISO/Non-ISO)

If you’ve ever stared at a part number like `DNC-63-200-PPV-A-S2` and wondered what it means, you’re not alone. The pneumatic cylinder model code is a compact language that encodes bore size, stroke, mounting style, cushioning, and more. In short: the model code tells you exactly which cylinder you have—and which one you need to replace. This guide breaks down both ISO and non-ISO cylinder codes so you can decode any part number on the spot, avoid ordering errors, and keep your line running.

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Why Cylinder Model Codes Matter (and Where They Hide)

Every pneumatic cylinder manufacturer uses a slightly different code system. However, the global standard for industrial cylinders is ISO 15552 (formerly ISO 6431), which covers tie-rod and profile cylinders. Non-ISO cylinders (often from brands like SMC, Festo, or Airtac) use similar logic but with brand-specific prefixes and suffixes.

The model code is usually stamped on the cylinder body, printed on the label, or listed on the original purchase order. Without it, you risk buying the wrong bore or stroke, which leads to downtime and costly returns.

Key fields you’ll find in almost any pneumatic cylinder model code:

• Bore size (mm)
• Stroke length (mm)
• Mounting style (e.g., flange, foot, trunnion)
• Cushioning type (adjustable, non-adjustable, or none)
• Piston rod threading and diameter
• Options (magnetic piston, rod end type, sealing material)

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ISO Cylinder Sizing: Breaking Down the Standard Code

ISO cylinders follow a predictable pattern. Let’s use a common example: `DNC-63-200-PPV-A-S2` (a Festo-style code, but the logic applies across ISO 15552).

1. Series / Type Prefix – `DNC` indicates a standard ISO cylinder (tie-rod or profile). Other prefixes: `DNU` (ISO compact), `DSBC` (ISO with integrated sensors), etc.

2. Bore Size (mm) – `63` means 63 mm bore diameter. This is the ISO cylinder sizing critical dimension—it determines force output. Standard ISO bores are 32, 40, 50, 63, 80, 100, 125, 160, 200, 250, 320 mm.

3. Stroke Length (mm) – `200` means 200 mm of travel. Stroke is custom in most cases, but the code always lists it after bore.

4. Cushioning – `PPV` stands for adjustable pneumatic cushioning at both ends. Other codes: `P` (non-adjustable), `PPS` (self-adjusting), or `N` (no cushioning).

5. Mounting / Variant – `A` often means basic version (no special mounting). But you’ll see codes like `S2` (rear lug), `MP2` (front flange), or `S6` (swivel eye). These are usually appended at the end.

6. Options – `S2` at the very end often refers to rod thread type or sensor slot variant. Some brands add `A` for magnetic piston, `K` for rod end with fork, etc.

> Pro tip: Always check the manufacturer’s datasheet for the exact meaning of suffix letters—they can vary even within ISO-compliant products.

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Decoding Non-ISO Cylinder Codes (SMC, Airtac, and Others)

Non-ISO cylinders are often cheaper or more compact, but their model codes are less standardized. Let’s look at a typical SMC code: `CDQ2B32-15DZ`.

• `C` – Magnetic piston (no `C` means no magnet)
• `D` – Series (compact cylinder)
• `Q2` – Compact type (non-ISO)
• `B` – Mounting style (e.g., B = basic, L = foot, F = flange)
• `32` – Bore size (mm)
• `15` – Stroke (mm)
• `DZ` – Options (e.g., D = auto switch position, Z = various)

Airtac codes are similar: `SC63X200` is a standard cylinder with 63 mm bore and 200 mm stroke. The `X` separates bore and stroke. Some non-ISO codes add `S` for standard, `LB` for foot mounting, or `CB` for nose mounting.

Common non-ISO pitfalls:

• Stroke is sometimes listed in inches (e.g., `SC50X2″`).
• Bore may be abbreviated (e.g., `SU32` = 32 mm compact).
• Mounting letters are not universal—always cross-reference with the brand’s catalog.

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Step-by-Step: How to Identify a Cylinder from Its Code

When you have a cylinder in hand but no datasheet, follow this practical workflow:

1. Measure the bore – Use calipers on the cylinder tube inner diameter (or outer diameter if you know the wall thickness). This confirms the first number in the code.

2. Measure the stroke – Extend the rod fully and measure from the face of the cylinder head to the rod end. This matches the stroke number.

3. Check the mounting style – Look at the cylinder’s feet, flanges, or trunnions. Match them to the suffix letters.

4. Look for the magnetic piston – If the cylinder has reed switch grooves or you see a magnet indicator, the code should have a `C` or `M` prefix.

5. Inspect the rod end – Is it male thread, female thread, or a clevis? This is often the last letter or number in the code.

If you’re replacing a cylinder and the code is worn off, you can use these measurements to find the correct match on our [standard cylinder](/products/cylinder/standard-cylinder/) or [compact cylinder](/products/cylinder/compact-cylinder/) pages.

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Common Mistakes When Reading Cylinder Codes

Even experienced engineers mix up these details. Here are the most frequent errors:

• Ignoring cushioning type – Non-adjustable cushioning (P) vs. adjustable (PPV) affects deceleration at high speeds. Replacing with the wrong type can cause impact damage.
• Confusing bore with outer diameter – ISO cylinders list bore, not OD. A 63 mm bore cylinder has an OD of about 70–80 mm depending on the profile.
• Forgetting the rod thread size – The code often includes `A` or `S2` for rod thread. If you skip this, your rod end fitting won’t fit.
• Assuming all ISO codes are universal – While ISO 15552 standardizes dimensions, manufacturers still use their own letters for mounting and options. Always verify with the brand’s chart.

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How to Order the Right Replacement (Without the Guesswork)

Once you’ve decoded the model code, ordering is straightforward. But if you’re unsure, here’s what to do:

• Check the brand and series – Look for a logo or name on the cylinder. This narrows down the code system.
• Use the manufacturer’s cross-reference – Most brands publish a “model designation” page in their catalog. Compare your code field by field.
• Measure twice, order once – Confirm bore, stroke, mounting, and rod thread before purchasing.

If your cylinder is obsolete or the code is unreadable, we can help. At Canuri, we stock both [standard ISO cylinders](/products/cylinder/standard-cylinder/) and [compact non-ISO models](/products/cylinder/compact-cylinder/), and our team can match your old part by dimensions and performance specs.

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Conclusion: Don’t Let a Code Slow You Down

Reading a pneumatic cylinder model code is a skill that saves time, money, and headaches. Whether it’s an ISO 15552 standard or a brand-specific non-ISO code, the structure is logical: series, bore, stroke, cushioning, mounting, and options. Keep this guide handy, and you’ll decode any cylinder in under a minute.

If you’re still unsure about a part number or need a replacement, contact Canuri with your old cylinder’s code or dimensions, and we’ll provide a fast, accurate quotation. We carry a wide range of spare parts for all major automation brands—so you can get back to production without delay.

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FAQ

#### H3: What does ISO 15552 mean in pneumatic cylinders?

ISO 15552 (formerly ISO 6431) is the international standard for pneumatic cylinders with tie-rod or profile construction. It defines bore sizes, mounting dimensions, and stroke ranges so that cylinders from different manufacturers are interchangeable. ISO cylinder sizing follows a fixed bore series (32, 40, 50, 63, etc.) and standardized mounting patterns.

#### H3: How do I know if my cylinder is ISO or non-ISO?

Check the cylinder body for a label or engraving. ISO cylinders often have a profile with slots for sensors and tie rods on the corners. Non-ISO cylinders may be round, compact, or have a different mounting flange pattern. If you see a code starting with “DNC,” “DSBC,” or “DNU,” it’s likely ISO; codes like “SC,” “MA,” or “CQ2” indicate non-ISO.

#### H3: Can I replace a non-ISO cylinder with an ISO one?

Yes, but only if the bore size, stroke, mounting dimensions, and port sizes match. ISO cylinders often have different overall lengths and mounting hole patterns. You may need adapter plates or new fittings. It’s safer to replace like-for-like unless you’re redesigning the entire actuator system.

#### H3: What is the difference between adjustable and non-adjustable cushioning in a cylinder code?

Adjustable cushioning (often marked “PPV” or “S”) allows you to tune the deceleration at the end of stroke using screws or needles. Non-adjustable cushioning (“P” or “N”) uses fixed orifices and cannot be changed. Adjustable is preferred for variable loads or high speeds; non-adjustable is fine for constant, low-speed applications.

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