This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X750, 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 SI40X750
The AirTAC Airtac SI40 Standard Cylinder SI40X750 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 750mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X750, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke750 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X750
- 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 SI40X750
The AirTAC SI40X750 is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 750 mm stroke. It delivers 628 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X750, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this specific SKU lacks a magnet (-S), so it cannot accept position sensors like the legacy CS1-B/DS1-B switches.
Airtac SI40 Standard Cylinder SI40X750 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X750 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X750 |
| Bore size | Ø40 mm |
| Stroke | 750 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 SAI40X750 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 SAI40X750 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 SI40X750
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×750 | 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 SI40X750 Is Used
Long-Stroke Diversion
Pushes packages across a 750 mm conveyor belt transfer, utilizing the 628 N push force at 0.5 MPa to overcome friction on the rollers.
Vertical Material Lift
Raises lightweight totes up to 32 kg in a storage rack, requiring external linear guides to prevent rod bending over the extended stroke.
Actuator Positioning
Shifts a tooling carriage along a production line, relying on the adjustable 27 mm air cushions to decelerate the load smoothly at stroke ends.
Replacing the Airtac SI40 Standard Cylinder SI40X750 with the SAI40X750
To replace the SI40X750, order the SAI40X750. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 port thread (PT/G/NPT), and the M12x1.25 rod-end thread. Because this is a 750 mm stroke, add external guides to prevent rod bending and side-load damage. Sizing both ways: a 32 mm bore yields 402 N push at 0.5 MPa, while a 50 mm bore yields 982 N. If load holding is required, note that a plain cylinder drifts on air loss—the cushion only decelerates. Use an external pilot check valve, a rod lock, or the SAIL/BSAI lock variants. For self-contained valve needs, explore the SAIF variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X750
- ✓ 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 SI40X750 FAQ
Yes, the SI40X750 is discontinued. The direct replacement is the AirTAC SAI40X750. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 750 mm stroke, 628 N force, G1/4 port, and mounting interface, so it fits existing fixtures directly.
This double-acting cylinder operates at 30-800 mm/s with a G1/4 port and M12x1.25 rod thread. Force ratings are: 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N push at 0.9 MPa, and a theoretical maximum of 128 kgf at 1.0 MPa.
Request a Quote for the SAI40X750
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X750 replacement — usually within 7-8 hours.