This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X400SCB, 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 SI125X400SCB
The AirTAC SI125 Standard Cylinder SI125X400SCB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 400mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X400SCB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke400 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X400SCB
- 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 SI125X400SCB
The AirTAC SI125X400SCB is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 400mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. The direct replacement is the SAI125X400SCB, which maintains the exact same ISO 15552 mounting interface, CB clevis, stroke, and output force.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds SAIL and BSAI lock variants the SI lacked.
Airtac SI125 Standard Cylinder SI125X400SCB Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X400SCB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X400SCB |
| Bore size | Ø125 mm |
| Stroke | 400 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 SAI125X400SCB 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 SAI125X400SCB 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 SI125X400SCB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×400 | 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 SI125X400SCB Is Used
Heavy Press Systems
Drives large platens applying 8590N of push force at 0.7MPa for assembling industrial components.
Pallet Lifting
Raises 313kg loads vertically using the 400mm stroke, requiring external guides to prevent rod bending.
Material Diversion
Actuates heavy-duty routing gates on high-capacity lines, utilizing the CB clevis for pivot motion.
Replacing the Airtac SI125 Standard Cylinder SI125X400SCB with the SAI125X400SCB
To replace the SI125X400SCB, order the SAI125X400SCB. It drops into existing fixtures via the ISO 15552 CB clevis mounting interface, matching the 125mm bore, 400mm stroke, G1/2 port, and M27x2 rod thread. If you need more force, the neighboring 160mm bore offers 10053N push at 0.5MPa; if less is required, the 100mm bore provides 3927N. The -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches. Because this is a 400mm stroke, use an external guide to prevent rod bending and side-load wear. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding, specify the SAIL lock variant or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X400SCB
- ✓ 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 SI125X400SCB FAQ
Yes, the SI125X400SCB is discontinued. The direct replacement is the SAI125X400SCB. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 400mm stroke, G1/2 port, and CB mounting.
It uses a G1/2 port. The thrust is 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a maximum theoretical force of 1251kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X400SCB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X400SCB replacement — usually within 7-8 hours.