This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X25N, 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 SI40X25N
The AirTAC Airtac SI40 Standard Cylinder SI40X25N is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 25mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X25N, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke25 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X25N
- 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 SI40X25N
The AirTAC SI40X25N is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 25mm stroke, delivering 628N push force at 0.5 MPa. This NBR-sealed unit features a G1/4 port and 16mm rod, but lacks a magnet for sensing. AirTAC replaced it with the SAI40X25N.
The SAI40X25N is a direct replacement matching the ISO 15552 mounting interface, bore, stroke, force and port. It upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure.
Airtac SI40 Standard Cylinder SI40X25N Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X25N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X25N |
| Bore size | Ø40 mm |
| Stroke | 25 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 SAI40X25N 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 SAI40X25N 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 SI40X25N
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×25 | 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 SI40X25N Is Used
Short-Stroke Clamping
Ideal for holding light workpieces during machining, utilizing the 628N push force within a compact 25mm travel.
Ejector Mechanisms
Provides rapid part ejection on assembly lines, operating at speeds between 30-800 mm/s via the G1/4 port.
Package Diverting
Suitable for actuating small diverters or gates on material handling conveyors where a 32kg lift margin is sufficient.
Replacing the Airtac SI40 Standard Cylinder SI40X25N with the SAI40X25N
To replace the SI40X25N, order the SAI40X25N and confirm the ISO 15552 interface, 40mm bore, 25mm stroke, G1/4 port and mounting accessory. Because this SKU lacks a magnet (-S), it cannot accept a CS1-B/DS1-B sensor. If you need higher force, the 50mm bore offers 982N push at 0.5 MPa; if you need less, the 32mm bore provides 402N. Note that a plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock or pilot check valve for load holding, or explore the SAIL or BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X25N
- ✓ 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 SI40X25N FAQ
Yes, the SI40X25N is discontinued. The direct replacement is the SAI40X25N, which shares the same ISO 15552 mounting interface, 40mm bore, 25mm stroke, force and G1/4 port.
The 40mm bore features a G1/4 port. It delivers 628N push and 528N pull at 0.5 MPa, 879N push at 0.7 MPa, 1130N push at 0.9 MPa, and a theoretical max of 128 kgf at 1.0 MPa.
Request a Quote for the SAI40X25N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X25N replacement — usually within 7-8 hours.