This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X70STC, 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 SI40X70STC
The AirTAC Airtac SI40 Standard Cylinder SI40X70STC 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 SAI40X70STC, 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 → SAI40X70STC
- 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 SI40X70STC
The AirTAC SI40X70STC is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 70mm stroke, and TC trunnion mount. Delivering 628N push force at 0.5MPa through a G1/4 port, it is replaced by the SAI40X70STC. This direct upgrade matches the original ISO 15552 mounting interface, bore, stroke, force, port and TC accessory.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The family adds SAIL, SAIF and BSAI variants the SI lacked. The -S magnet works with CS1-B/DS1-B switches, and Viton H seals raise temps to 150C.
Airtac SI40 Standard Cylinder SI40X70STC Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X70STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X70STC |
| 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 SAI40X70STC 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 SAI40X70STC 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 SI40X70STC
| 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 SI40X70STC Is Used
Package Diversion
Drives a 70mm stroke deflector gate on a packaging line, using the 628N push force to route cartons at 30-800 mm/s.
Clamp Actuation
Secures medium-duty workpieces during machining via the TC trunnion mount, absorbing side loads while clamping with 528N pull force.
Replacing the Airtac SI40 Standard Cylinder SI40X70STC with the SAI40X70STC
To replace the SI40X70STC, order the SAI40X70STC. Verify the ISO 15552 TC trunnion mount, 40mm bore, 70mm stroke, G1/4 port (PT/G/NPT), and the -S magnet for CS1-B/DS1-B sensors. Sizing both ways: a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. This 40mm bore provides 628N push and 528N pull at 0.5MPa. Note: a plain cylinder drifts on air loss—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 → SAI40X70STC
- ✓ 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 SI40X70STC FAQ
Yes, the AirTAC SI40X70STC is discontinued. The direct replacement is the SAI40X70STC. It shares the identical ISO 15552 mounting interface, 40mm bore, 70mm stroke, output force, G1/4 port and TC trunnion mount, fitting existing fixtures perfectly.
This double-acting cylinder has a 16mm rod, M12x1.25 thread, 27mm cushion, and G1/4 port. Speed is 30-800 mm/s. Force ratings: push 628N and pull 528N at 0.5MPa, push 879N at 0.7MPa, push 1130N at 0.9MPa, and a theoretical max of 128 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X70STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X70STC replacement — usually within 7-8 hours.