This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X270, 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 SI40X270
The AirTAC SI40 Standard Cylinder SI40X270 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 270mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X270, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke270 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X270
- 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 SI40X270
The AirTAC SI40X270 is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 270mm stroke, delivering 628N push and 528N pull at 0.5MPa. The direct replacement is the SAI40X270, matching the G1/4 port, M12x1.25 thread, and 27mm cushions. This SKU lacks a magnet and cannot accept a sensor.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure, while the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked. Rod options include SUS420J2 or SUS304, and Viton H seals extend heat to 150C.
Airtac SI40 Standard Cylinder SI40X270 Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X270 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X270 |
| Bore size | Ø40 mm |
| Stroke | 270 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 SAI40X270 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 SAI40X270 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 SI40X270
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×270 | 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 SI40X270 Is Used
Package Diverting
Actuates routing gates on packaging lines using the 528N pull force to redirect cartons at 30-800 mm/s.
Clamp Actuation
Drives small machining clamps delivering 628N push force, relying on external check valves to hold position.
Replacing the Airtac SI40 Standard Cylinder SI40X270 with the SAI40X270
To replace this SI40X270 with the SAI40X270, verify the ISO 15552 mounting interface, 270mm stroke, G1/4 port, and mounting accessory. Because this specific SKU has no -S magnet, it cannot accept CS1-B/DS1-B sensors; order the magnet option if position detection is needed. For sizing alternatives, a 32mm bore yields 402N push, while a 50mm bore provides 982N at 0.5MPa. A plain cylinder drifts on air loss since cushions only decelerate; use an external rod lock, pilot check valve, or SAIL/BSAI variant for load holding. With a 270mm stroke, ensure guide rails prevent rod bending under side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X270
- ✓ 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 SI40X270 FAQ
Yes, the SI40X270 is discontinued. The direct replacement is the SAI40X270. It shares the same ISO 15552 mounting interface, 40mm bore, 270mm stroke, 628N force, G1/4 port, and accessories, fitting existing fixtures perfectly.
The 40mm bore features a G1/4 air port. It delivers 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa. It operates at 30-800 mm/s.
Request a Quote for the SAI40X270
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X270 replacement — usually within 7-8 hours.