This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X25SH, 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 SI40X25SH
The AirTAC Airtac SI40 Standard Cylinder SI40X25SH 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 SAI40X25SH, 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 → SAI40X25SH
- 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 SI40X25SH
The AirTAC SI40X25SH is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 25mm stroke. Delivering 628N push force at 0.5MPa, it features a G1/4 port and M12x1.25 rod thread. The direct replacement is the SAI40X25SH, matching the exact ISO 15552 mounting interface, bore, stroke, output force, port and accessories.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The -H suffix denotes a Viton H seal, extending operating temperature from -20 to +70 C up to 0-150 C. With the -S magnet, it supports legacy CS1-B/DS1-B switches.
Airtac SI40 Standard Cylinder SI40X25SH Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X25SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X25SH |
| 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 SAI40X25SH 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 SAI40X25SH 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 SI40X25SH
| 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 SI40X25SH Is Used
Short-Stroke Clamping
Ideal for holding light workpieces in machining fixtures using its 25mm travel and 628N push force at 0.5MPa.
Ejector Mechanisms
Provides rapid part ejection on small assembly lines, operating efficiently at 30-800mm/s within tight spaces.
Diverting Arms
Drives compact routing gates on conveyors where a 32kg vertical lift capacity and short stroke are sufficient.
Replacing the Airtac SI40 Standard Cylinder SI40X25SH with the SAI40X25SH
To replace the SI40X25SH, order the SAI40X25SH. Confirm the ISO 15552 mounting fixture, 40mm bore, 25mm stroke, G1/4 port (PT/G/NPT thread), and the -S magnet for CS1-B/DS1-B sensors. The SAI family adds SAIL (air-released lock), SAIF (built-in 4M valve) and BSAI (clamp-lock) variants the SI lacked. For sizing, the 628N push at 0.5MPa gives a safe 377N working load; if more force is needed, the neighbouring 50mm bore offers 982N. Note: a plain cylinder drifts on air loss as the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X25SH
- ✓ 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 SI40X25SH FAQ
Yes, the AirTAC SI40X25SH is discontinued. The direct replacement is the SAI40X25SH. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 40mm bore, 25mm stroke, 628N force, G1/4 port and mounting accessories.
It features a G1/4 air port. The force ratings are: 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X25SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X25SH replacement — usually within 7-8 hours.