This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X525S, with the same bore, stroke, output force, port and mounting, so it fits the same application. The SAI replacement keeps the same ISO 15552 mounting interface, bore, stroke, output force and accessories, so it drops straight into existing fixtures. It is the current-production version of this cylinder with an upgraded piston seal.
Airtac SI40 Standard Cylinder SI40X525S
The AirTAC SI40 Standard Cylinder SI40X525S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 525mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X525S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke525 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X525S
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SI40 Standard Cylinder SI40X525S
The AirTAC SI40X525S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 525mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X525S. This direct upgrade shares the exact interface, bore, stroke, force and mounting.
The SAI features an upgraded piston seal with two Y-shaped elements for low start-up pressure. The SAI family adds SAIL, SAIF and BSAI lock variants. The -S magnet works with CS1-B/DS1-B switches.
Airtac SI40 Standard Cylinder SI40X525S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X525S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X525S |
| Bore size | Ø40 mm |
| Stroke | 525 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| Fluid | Air (filtered by 40µm element) |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI40X525S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X525S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40X525S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×525 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Legacy SI-family variants: SID (double rod), SIJ (adjustable stroke) — each maps to its SAI equivalent (SID→SAID, SIJ→SAIJ). Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B).
Where the Airtac SI40 Standard Cylinder SI40X525S Is Used
Long-Stroke Diversion
Pushes packages across a transfer lane using the full 525mm travel, relying on external guides to prevent rod bending during the extended cycle.
Vertical Lift Gates
Raises lightweight access gates.
Pneumatic Positioning
Shifts tooling carriages between stations. The built-in magnet enables CS1-B/DS1-B sensors to confirm end-of-stroke positions.
Replacing the Airtac SI40 Standard Cylinder SI40X525S with the SAI40X525S
To replace the SI40X525S, order the SAI40X525S direct: confirm the ISO 15552 mounting interface, 525mm stroke, G1/4 port (PT/G/NPT) and mounting accessory. The -S magnet enables CS1-B/DS1-B sensors. Sizing both ways: a 50mm bore gives 982N push @0.5MPa, while a 32mm bore yields 402N. For the 525mm stroke, use external guides to prevent rod-bending under side loads. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or SAIL/BSAI variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X525S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40X525S FAQ
Yes, the SI40X525S is discontinued. The direct replacement is the SAI40X525S. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 525mm stroke, 628N force, G1/4 port and mounting interface.
The 40mm bore features a G1/4 air port and a 16mm rod. Force ratings are: 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X525S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X525S replacement — usually within 7-8 hours.