This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X1275S, 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 SI40X1275S
The AirTAC Airtac SI40 Standard Cylinder SI40X1275S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 1275mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X1275S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke1275 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X1275S
- 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 SI40X1275S
The AirTAC SI40X1275S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 1275mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. Because 1275mm exceeds the 1200mm standard maximum, this is a non-standard made-to-order length. The direct replacement is the SAI40X1275S, matching the interface, force, and mounting.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. It also adds SAIL, SAIF, and BSAI lock variants absent in the SI line. The built-in magnet supports legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches.
Airtac SI40 Standard Cylinder SI40X1275S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X1275S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X1275S |
| Bore size | Ø40 mm |
| Stroke | 1275 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 SAI40X1275S 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 SAI40X1275S 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 SI40X1275S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×1275 | 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 SI40X1275S Is Used
Long-Stroke Diversion
Drives large package pushers across wide conveyor belts, utilizing the full 1275mm travel to reroute heavy goods smoothly.
Automated Material Transfer
Shifts workpieces between distant machining stations, relying on adjustable end cushions to decelerate the 40mm bore safely.
Replacing the Airtac SI40 Standard Cylinder SI40X1275S with the SAI40X1275S
To replace the SI40X1275S, order the SAI40X1275S. Confirm the ISO 15552 mounting interface, the G1/4 port, and your mounting accessory (LB, FA, TC, etc.). The -S denotes a magnet, so ensure you specify it to retain switch compatibility. When sizing, a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N; this 40mm bore gives 628N. Note that 1275mm is a non-standard stroke exceeding the 1200mm max, so expect a made-to-order lead time. For a 1275mm stroke, external guides are strongly recommended to prevent rod bending and side-load damage. A plain cylinder drifts without live air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X1275S
- ✓ 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 SI40X1275S FAQ
Yes, the SI40X1275S is discontinued. The direct replacement is the SAI40X1275S. It is dimensionally interchangeable per ISO 15552, maintaining the same 40mm bore, 1275mm stroke, 628N force, G1/4 port, and mounting interface.
The 40mm bore uses a G1/4 air port and an M12x1.25 rod thread. Force output is 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, with a theoretical maximum of 128kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X1275S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X1275S replacement — usually within 7-8 hours.