This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X125CB, 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 SI40X125CB
The AirTAC Airtac SI40 Standard Cylinder SI40X125CB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X125CB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke125 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X125CB
- 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 SI40X125CB
The AirTAC SI40X125CB is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 125mm stroke. Delivering 628N push force at 0.5MPa via a G1/4 port, it is directly replaced by the SAI40X125CB. This direct upgrade shares the exact ISO 15552 mounting interface, CB clevis, and output force. The SAI features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life.
Because this specific SKU lacks the -S magnet suffix, it cannot accept a magnetic sensor. If you need position detection, order the SAI equivalent with an S suffix to use current AirTAC switches (replacing the legacy CS1-B/DS1-B set). For high-heat environments beyond the standard -20 to +70C range, both series offer a Viton H seal option (0-150C). Note that a plain cylinder does not hold load on air loss; for that, explore the SAIL or BSAI lock variants.
Airtac SI40 Standard Cylinder SI40X125CB Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X125CB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X125CB |
| Bore size | Ø40 mm |
| Stroke | 125 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 SAI40X125CB 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 SAI40X125CB 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 SI40X125CB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×125 | 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 SI40X125CB Is Used
Carton Diverting
Ideal for pushing light packaging on a conveyor line, utilizing the 125mm stroke and 628N push force to redirect cardboard cartons at high speeds.
Small Part Ejection
Provides reliable ejection of machined small parts from a fixture, where the CB clevis mount accommodates slight angular misalignment during the push stroke.
Replacing the Airtac SI40 Standard Cylinder SI40X125CB with the SAI40X125CB
To replace the discontinued SI40X125CB, order the SAI40X125CB. Confirm your ISO 15552 interface, 40mm bore, 125mm stroke, G1/4 port, and CB clevis mounting accessory. When sizing both ways, a neighbouring 32mm bore yields 402N push at 0.5MPa, while a 50mm bore yields 982N. This 40mm bore provides 628N push and 528N pull at 0.5MPa, with a theoretical maximum of 128kgf at 1.0MPa. Operating speed is 30-800mm/s. Remember that a standard cylinder drifts when air is lost—the cushion only decelerates near stroke end. For load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variants. If you need self-contained valve control, the SAIF variant (bores 32-100) integrates a 4M valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X125CB
- ✓ 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 SI40X125CB FAQ
Yes, the AirTAC SI40X125CB is discontinued. The direct replacement is the SAI40X125CB. It is dimensionally interchangeable per ISO 15552, retaining the same 40mm bore, 125mm stroke, G1/4 port, CB clevis mount, and output force.
This double-acting cylinder has a G1/4 port. It delivers a push force of 628N and a pull force of 528N at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical maximum of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40X125CB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X125CB replacement — usually within 7-8 hours.