This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X270CB, 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 SI40X270CB
The AirTAC Airtac SI40 Standard Cylinder SI40X270CB 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 SAI40X270CB, 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 → SAI40X270CB
- 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 SI40X270CB
The AirTAC SI40X270CB is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 270mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X270CB. This direct upgrade retains the exact CB clevis mount, M12x1.25 rod thread, and 27mm cushions, fitting existing fixtures seamlessly.
The SAI features an upgraded piston seal with two Y-shaped elements for low start-up pressure and long life. This SKU lacks a magnet (-S), so it cannot take a CS1-B/DS1-B sensor. The SAI family also adds SAIL, SAIF, and BSAI lock variants.
Airtac SI40 Standard Cylinder SI40X270CB Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X270CB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X270CB |
| 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 SAI40X270CB 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 SAI40X270CB 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 SI40X270CB
| 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 SI40X270CB Is Used
Package Diversion
Actuates routing gates on packaging lines, utilizing the 628N push force to smoothly redirect cartons at 30-800 mm/s speeds.
Clamp Actuation
Provides reliable clamping pressure for light machining fixtures, taking advantage of the 270mm stroke to accommodate varying part widths.
Material Ejection
Ejects finished components from automated workstations, using the CB clevis mount to handle off-axis loads safely during the ejection cycle.
Replacing the Airtac SI40 Standard Cylinder SI40X270CB with the SAI40X270CB
To replace the SI40X270CB, order the SAI40X270CB. Confirm the ISO 15552 interface, 40mm bore, 270mm stroke, G1/4 port (PT/G/NPT), CB clevis mounting, and non-magnetic rod. Because this stroke exceeds 300mm? No, at 270mm it is under the 300mm threshold, but always verify guide alignment to prevent rod bending. Sizing both ways: a neighbouring 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variant. Since there is no magnet, position sensing is impossible without a retrofit.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X270CB
- ✓ 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 SI40X270CB FAQ
Yes, the SI40X270CB is discontinued. The direct replacement is the SAI40X270CB. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 270mm stroke, G1/4 port, and CB clevis mounting interface.
This double-acting cylinder features a G1/4 air port and provides 628N push / 528N pull at 0.5 MPa, 879N push at 0.7 MPa, 1130N at 0.9 MPa, and a theoretical max of 128 kgf at 1.0 MPa. It operates at 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X270CB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X270CB replacement — usually within 7-8 hours.