This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X250CB, 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 SI125 Standard Cylinder SI125X250CB
The AirTAC SI125 Standard Cylinder SI125X250CB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 250mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X250CB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke250 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X250CB
- 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 SI125 Standard Cylinder SI125X250CB
The AirTAC SI125X250CB is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore and 250 mm stroke. It delivers 6136 N push and 5734 N pull force at 0.5 MPa, utilizing a G1/2 port and M27x2 rod thread. Because this SI series is end-of-life, you should order the direct replacement: the SAI125X250CB. It maintains the identical ISO 15552 mounting interface, CB clevis mount, output force, and port size, fitting seamlessly into existing fixtures.
The SAI upgrade introduces an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this specific SKU lacks a magnet (-S), meaning it cannot accept position sensors. The SAI family also adds variants the SI lacked, such as the SAIL air-released lock and BSAI clamp-lock for load holding.
Airtac SI125 Standard Cylinder SI125X250CB Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X250CB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X250CB |
| Bore size | Ø125 mm |
| Stroke | 250 mm |
| Acting type | Double acting |
| Port size | G1/2 |
| Rod thread | M27×2.0 |
| 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 – 500 mm/s |
| Cushion | Adjustable, 40 mm |
| Max standard stroke | Up to 1500 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI125X250CB carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø125mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 6136 N | 5734 N |
| 0.7 MPa | 8590 N | — |
| Max (@1.0 MPa) | 1251 kgf | |
The SAI125X250CB produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI125 Standard Cylinder SI125X250CB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | 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 SI125 Standard Cylinder SI125X250CB Is Used
Heavy Stamping Press
Drives large heavy-duty stamping and forming dies requiring up to 8590 N of push force at 0.7 MPa, utilizing the robust 32 mm piston rod.
Automated Clamp Fixture
Secures large fabricated components during machining via the CB clevis mount, accommodating the 30-500 mm/s operating speed.
Replacing the Airtac SI125 Standard Cylinder SI125X250CB with the SAI125X250CB
To replace the discontinued SI125X250CB, order the SAI125X250CB, confirming the ISO 15552 interface, 125 mm bore, 250 mm stroke, G1/2 port, and CB clevis mounting accessory. When sizing, note the 6136 N push force at 0.5 MPa; if you need more power, the neighbouring 160 mm bore offers 10053 N. If less force is acceptable, the 100 mm bore provides 3927 N. Because this is a plain cylinder without a magnet, it cannot take CS1-B/DS1-B sensors. A standard cylinder does not hold load on air loss—the cushion only decelerates—so for load holding, consider the SAIL or BSAI lock variants, or an external pilot check valve. For this 250 mm stroke, ensure proper guide alignment to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X250CB
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI125 Standard Cylinder SI125X250CB FAQ
Yes, the AirTAC SI125X250CB is discontinued. The direct replacement is the SAI125X250CB. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 250 mm stroke, G1/2 port, CB mount, and force ratings.
This double-acting cylinder uses a G1/2 air port. It generates 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N push at 0.9 MPa, and a theoretical maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X250CB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X250CB replacement — usually within 7-8 hours.