This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X240, 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 SI40X240
The AirTAC Airtac SI40 Standard Cylinder SI40X240 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 240mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X240, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke240 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X240
- 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 SI40X240
The AirTAC SI40X240 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 240mm stroke, delivering 628N push force at 0.5MPa. The direct replacement is the SAI40X240, maintaining the exact G1/4 port, M12x1.25 rod thread, and mounting interface.
Because this specific SKU lacks the -S magnet suffix, it cannot accept a position sensor. The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure, and adds SAIL or BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40X240 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X240 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X240 |
| Bore size | Ø40 mm |
| Stroke | 240 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 SAI40X240 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 SAI40X240 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 SI40X240
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×240 | 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 SI40X240 Is Used
Package Diversion
Actuates routing gates on 240mm strokes to redirect small to mid-weight cartons between conveyor belts.
Clamp Actuation
Provides 628N of push force at 0.5MPa to secure medium workpieces during light machining or assembly.
Replacing the Airtac SI40 Standard Cylinder SI40X240 with the SAI40X240
To replace the SI40X240, order the SAI40X240 and confirm your ISO 15552 mounting accessories (LB, FA, TC, etc.), G1/4 port thread, and 240mm stroke. Since this SKU has no -S magnet, you cannot mount legacy CS1-B/DS1-B sensors; if sensing is required, switch to an SAI40X240S. Sizing both ways: the 40mm bore gives 628N push at 0.5MPa, whereas a 32mm bore yields 402N and a 50mm bore yields 982N. For stroke lengths at or above 300mm, use a guide to prevent rod bending and side-load wear. Note that a standard cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X240
- ✓ 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 SI40X240 FAQ
Yes, the AirTAC SI40X240 is discontinued. The direct replacement is the SAI40X240. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 40mm bore, 240mm stroke, force, and G1/4 port.
The 40mm bore delivers 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. Operating speed is 30-800mm/s.
Request a Quote for the SAI40X240
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X240 replacement — usually within 7-8 hours.