This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X70S, 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 SI40X70S
The AirTAC Airtac SI40 Standard Cylinder SI40X70S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 70mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X70S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke70 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X70S
- 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 SI40X70S
The AirTAC SI40X70S is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore and 70 mm stroke, delivering 628 N push force at 0.5 MPa. It has been superseded by the SAI40X70S, a direct replacement retaining the exact interface, G1/4 port, and M12x1.25 rod thread. The SAI features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life.
The -S suffix indicates a piston magnet for legacy CS1-B/DS1-B sensors, while the SAI accepts current AirTAC switches. A plain cylinder drifts on air loss; for load holding, consider the SAIL lock or BSAI clamp-lock variants.
Airtac SI40 Standard Cylinder SI40X70S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X70S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X70S |
| Bore size | Ø40 mm |
| Stroke | 70 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 SAI40X70S 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 SAI40X70S 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 SI40X70S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×70 | 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 SI40X70S Is Used
Component Clamping
Ideal for securing mid-weight machined parts during milling or drilling, utilizing the 628 N push force to hold firm against cutting vibration.
Package Diverting
Provides reliable 70 mm stroke actuation for routing smaller cartons on packaging lines, with adjustable cushions ensuring gentle stops.
Replacing the Airtac SI40 Standard Cylinder SI40X70S with the SAI40X70S
To replace the SI40X70S, order the SAI40X70S and confirm the ISO 15552 mounting interface, 70 mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The -S magnet is present for position sensing. If you need more force, the neighbouring 50 mm bore offers 982 N push at 0.5 MPa; if less is required, the 32 mm bore provides 402 N. Because this is a double-acting cylinder, it will not hold a load without live air—the cushion only decelerates. For secure holding, use an external pilot check valve or explore the SAIL air-released lock and BSAI clamp-lock options. The SAIF variant with a built-in 4M valve is also available for bores 32-100.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X70S
- ✓ 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 SI40X70S FAQ
Yes, the AirTAC SI40X70S is discontinued. The direct replacement is the SAI40X70S. It is dimensionally interchangeable per ISO 15552, matching the 40 mm bore, 70 mm stroke, output force, G1/4 port, and mounting fixtures.
The 40 mm bore features a G1/4 air port and a 16 mm rod. It delivers 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 SAI40X70S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X70S replacement — usually within 7-8 hours.