This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X250CA, 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 SI40X250CA
The AirTAC Airtac SI40 Standard Cylinder SI40X250CA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X250CA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X250CA
- 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 SI40X250CA
The AirTAC SI40X250CA is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 250mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI40X250CA. This direct upgrade shares the exact CA clevis mounting, M12x1.25 rod thread, and dimensions, fitting your existing fixtures perfectly.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. For load holding, note the cushion only decelerates; use a pilot check valve or SAIL lock variant. This no-S SKU lacks a magnet and cannot take a sensor.
Airtac SI40 Standard Cylinder SI40X250CA Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X250CA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X250CA |
| Bore size | Ø40 mm |
| Stroke | 250 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 SAI40X250CA 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 SAI40X250CA 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 SI40X250CA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×250 | 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 SI40X250CA Is Used
Package Diversion
Actuates routing gates on packaging lines, using the 250mm stroke to shift parcels cleanly between adjacent belt lanes.
Clamp Actuation
Provides reliable 628N push force at 0.5MPa to secure mid-weight workpieces in machining and assembly fixtures.
Stopper Arm Control
Drives pneumatic stop arms at roller conveyor endpoints, holding back product flow until the downstream station is clear.
Replacing the Airtac SI40 Standard Cylinder SI40X250CA with the SAI40X250CA
To replace the SI40X250CA, order the SAI40X250CA. Confirm the ISO 15552 interface, 40mm bore, 250mm stroke, G1/4 port (PT/G/NPT), and CA clevis mounting. This no-magnet SKU cannot accept a CS1-B/DS1-B sensor. Sizing both ways: a 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. At 250mm stroke, ensure guide alignment to prevent rod bending and side-load wear. The plain cylinder does not hold load without live air; for drop prevention, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. The SAIF variant adds a built-in valve if needed.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X250CA
- ✓ 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 SI40X250CA FAQ
Yes, the SI40X250CA is discontinued. The direct replacement is the SAI40X250CA. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 250mm stroke, 628N force, G1/4 port, and CA clevis mounting.
This double-acting cylinder uses a G1/4 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. Speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X250CA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X250CA replacement — usually within 7-8 hours.