This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X155S, 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 SI40X155S
The AirTAC Airtac SI40 Standard Cylinder SI40X155S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 155mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X155S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke155 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X155S
- 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 SI40X155S
The AirTAC SI40X155S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore, 155mm stroke, and a G1/4 port. Delivering 628N push force at 0.5MPa, it is replaced by the direct replacement SAI40X155S, which shares the exact mounting interface, bore, and output force.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SI-S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL lock, SAIF valve, and BSAI clamp variants.
Airtac SI40 Standard Cylinder SI40X155S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X155S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X155S |
| Bore size | Ø40 mm |
| Stroke | 155 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 SAI40X155S 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 SAI40X155S 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 SI40X155S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×155 | 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 SI40X155S Is Used
Component Clamping
Secures mid-weight machined parts during milling or drilling, utilizing the 628N push force at 0.5MPa for rigid workholding.
Package Diverting
Actuates sorting gates on packaging lines where a 155mm stroke pushes cartons smoothly onto adjacent lanes.
Pallet Stops
Functions as a pneumatic stop pin in low-profile conveyor endpoints, halting empty pallets safely before the packing station.
Replacing the Airtac SI40 Standard Cylinder SI40X155S with the SAI40X155S
To replace this SI40X155S, order the SAI40X155S: confirm the ISO 15552 interface, 40mm bore, 155mm stroke, G1/4 port (PT/G/NPT), and your mounting accessory. The -S magnet lets you use CS1-B/DS1-B switches. If you need more force, the 50mm bore offers 982N push at 0.5MPa; if less is acceptable, the 32mm bore gives 402N. A plain cylinder drifts on air loss—the cushion only decelerates—so use a pilot check valve or the SAIL/BSAI lock variant for load holding. The 155mm stroke is under the 300mm side-load threshold, but always guide the rod to prevent bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X155S
- ✓ 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 SI40X155S FAQ
Yes, the AirTAC SI40X155S is discontinued. The direct replacement is the SAI40X155S. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 155mm stroke, output force, G1/4 port, and mounting interface.
At 0.5MPa it provides 628N push and 528N pull force. At 0.7MPa push is 879N, and at 0.9MPa it is 1130N. The theoretical max force is 128kgf at 1.0MPa. Operating speed ranges from 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X155S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X155S replacement — usually within 7-8 hours.