This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X250H, 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 SI125X250H
The AirTAC SI125 Standard Cylinder SI125X250H 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 SAI125X250H, 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 → SAI125X250H
- 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 SI125X250H
The AirTAC SI125X250H is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore, 250 mm stroke, and a high-temperature Viton H seal (0-150 C). Delivering 6136 N push force at 0.5 MPa, it includes a 32 mm rod, M27x2 thread, and a G1/2 port.
The direct replacement is the SAI125X250H, sharing the same ISO 15552 mounting interface, force, and port. The SAI upgrades the piston seal to two Y-shaped one-way elements for low start-up pressure. Without a -S magnet, this SKU cannot take a sensor. For load holding, use an external rod lock or SAIL variant, as cushions only decelerate.
Airtac SI125 Standard Cylinder SI125X250H Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X250H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X250H |
| 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 SAI125X250H 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 SAI125X250H 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 SI125X250H
| 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 SI125X250H Is Used
Heavy Stamping
Drives large press dies with 6136 N thrust at 0.5 MPa, utilizing the 40 mm adjustable cushion to absorb impact.
Pallet Handling
Shifts heavy loaded pallets, where the 125 mm bore and G1/2 port deliver the volume needed for rapid actuation.
High-Tact Forming
Operates in heated forming stations up to 150 C using the Viton H seal, maintaining reliable clamping force.
Replacing the Airtac SI125 Standard Cylinder SI125X250H with the SAI125X250H
To replace the SI125X250H, order the SAI125X250H, confirming the ISO 15552 interface, 125 mm bore, 250 mm stroke, G1/2 port, and Viton H seal. Without a -S suffix, this SKU cannot accept a magnetic switch. If downsizing, the 100 mm bore offers 3927 N push; if upsizing, the 160 mm bore provides 10053 N. Because it lacks a lock, use a pilot check valve or SAIL/BSAI variant to hold loads. For this 250 mm stroke, ensure guide alignment to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X250H
- ✓ 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 SI125X250H FAQ
Yes, the SI125X250H is discontinued. The direct replacement is the SAI125X250H. It shares the same ISO 15552 mounting interface, 125 mm bore, 250 mm stroke, force, and G1/2 port, fitting existing fixtures perfectly.
The G1/2 port feeds a 125 mm bore yielding 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N at 0.9 MPa, and a max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X250H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X250H replacement — usually within 7-8 hours.