This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X250TC, 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 SI125X250TC
The AirTAC SI125 Standard Cylinder SI125X250TC 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 SAI125X250TC, 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 → SAI125X250TC
- 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 SI125X250TC
The AirTAC SI125X250TC is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 250mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. The direct replacement is the SAI125X250TC, retaining the exact TC trunnion mount, M27x2 rod thread, and output force.
Upgrading to the SAI brings a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Because this specific SKU lacks the -S magnet, it cannot accept position sensors.
Airtac SI125 Standard Cylinder SI125X250TC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X250TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X250TC |
| 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 SAI125X250TC 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 SAI125X250TC 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 SI125X250TC
| 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 SI125X250TC Is Used
Heavy Press Clamping
Generates 8590N at 0.7MPa to secure large steel fabrications during machining or welding operations.
Injection Mold Ejection
Provides the robust 125mm bore push force required to eject dense plastic components from heavy industrial molds.
Replacing the Airtac SI125 Standard Cylinder SI125X250TC with the SAI125X250TC
To replace the SI125X250TC, order the SAI125X250TC. Verify the ISO 15552 TC trunnion interface, 125mm bore, 250mm stroke, G1/2 port, and M27x2 thread. If sizing alternatives, the neighboring 100mm bore yields 3927N push at 0.5MPa, while the 160mm bore provides 10053N. For load holding, note that a plain cylinder drifts on air loss—the cushion only decelerates. Use an external pilot check valve or explore the SAIL or BSAI lock variants. If your stroke exceeds 300mm, add external guides to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X250TC
- ✓ 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 SI125X250TC FAQ
Yes, the SI125X250TC is discontinued. The direct replacement is the SAI125X250TC. It is dimensionally interchangeable per ISO 15552, matching the bore, stroke, force, G1/2 port, and TC mounting interface.
This double-acting cylinder features a G1/2 port. It delivers 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N at 0.9MPa, and a theoretical max of 1251kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X250TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X250TC replacement — usually within 7-8 hours.