This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X1270S, 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 SI40X1270S
The AirTAC Airtac SI40 Standard Cylinder SI40X1270S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 1270mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X1270S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke1270 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X1270S
- 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 SI40X1270S
The AirTAC SI40X1270S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 1270mm stroke. Because 1270mm exceeds the 1200mm standard maximum for this bore, it is a non-standard made-to-order unit. It delivers 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced the SI family with the SAI series; the SAI40X1270S is the direct replacement, matching the ISO 15552 mounting interface, bore, stroke, force, and port size.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. The original SI utilized CS1-B/DS1-B legacy sensors, while the SAI uses current AirTAC switches. Rod material options include carbon steel, SUS420J2, or SUS304, and a Viton H seal raises operating temperature to 150C.
Airtac SI40 Standard Cylinder SI40X1270S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X1270S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X1270S |
| Bore size | Ø40 mm |
| Stroke | 1270 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 SAI40X1270S 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 SAI40X1270S 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 SI40X1270S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×1270 | 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 SI40X1270S Is Used
Long-Stroke Diversion
Pushes packages across a wide conveyor belt sorting line using the full 1270mm travel distance.
Pallet Push-Off
Acts as a horizontal ejector for light pallets, safely moving loads within the 32kg vertical lift margin.
Material Lowering
Lowers components down a long vertical path, requiring external guides to manage rod side-load.
Replacing the Airtac SI40 Standard Cylinder SI40X1270S with the SAI40X1270S
To replace the SI40X1270S, order the SAI40X1270S, confirming the ISO 15552 mounting interface, M12x1.25 rod thread, G1/4 port, and the -S magnet for current AirTAC switches. When sizing, a 32mm bore offers 402N push at 0.5MPa, while a 50mm bore provides 982N; this 40mm bore yields 628N push and 528N pull at 0.5MPa, with a theoretical max of 128kgf at 1.0MPa. Because the 1270mm stroke exceeds the 1200mm standard maximum, it requires made-to-order handling, and at this length you must use external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X1270S
- ✓ 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 SI40X1270S FAQ
Yes, the SI40X1270S is discontinued. The direct replacement is the AirTAC SAI40X1270S. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 40mm bore, 1270mm stroke, 628N force, and G1/4 port. You can install it directly into existing fixtures.
This double-acting cylinder features a G1/4 air port and an M12x1.25 rod thread. The force output is 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum of 128kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X1270S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X1270S replacement — usually within 7-8 hours.