This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X275SH, 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 SI125X275SH
The AirTAC SI125 Standard Cylinder SI125X275SH is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 275mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X275SH, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke275 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X275SH
- 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 SI125X275SH
The AirTAC SI125X275SH is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore, 275mm stroke, G1/2 port, and a high-temperature Viton H seal (0-150 C). Delivering 6136 N push force at 0.5 MPa, it is replaced by the SAI125X275SH. This direct successor shares identical ISO 15552 mounting dimensions, bore, and output, fitting existing fixtures perfectly.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. The original SI magnet (-S) works with legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL and BSAI lock variants the SI lacked.
Airtac SI125 Standard Cylinder SI125X275SH Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X275SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X275SH |
| Bore size | Ø125 mm |
| Stroke | 275 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 SAI125X275SH 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 SAI125X275SH 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 SI125X275SH
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×275 | 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 SI125X275SH Is Used
Heavy Press Clamping
Ideal for exerting high clamping force on large metal fabrication parts, utilizing the 6136 N push force at 0.5 MPa to hold components securely during machining.
High-Tact Forming
Suitable for heavy-duty forming or stamping presses where the 275mm stroke provides deep draw length and the Viton H seal withstands elevated ambient heat.
Replacing the Airtac SI125 Standard Cylinder SI125X275SH with the SAI125X275SH
To replace the SI125X275SH, order the SAI125X275SH, confirming the ISO 15552 interface, 275mm stroke, G1/2 port, and high-temp Viton H seal. The SAI drops into existing mounts without changes. When sizing, neighbouring bores offer different force classes: the 100mm bore yields 3927 N push at 0.5 MPa, while the 160mm bore yields 10053 N. At 0.7 MPa, this 125mm bore outputs 8590 N. Because the 275mm stroke is relatively long, ensure adequate guide support to prevent rod bending and side-load wear. A plain cylinder does not hold load on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X275SH
- ✓ 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 SI125X275SH FAQ
Yes, the SI125X275SH is discontinued. The direct replacement is the SAI125X275SH. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 275mm stroke, G1/2 port, and mounting interface. The SAI features an upgraded two Y-shaped piston seal for longer life.
The bore has a G1/2 air port. At 0.5 MPa it provides 6136 N push and 5734 N pull force. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical maximum force is 1251 kgf at 1.0 MPa. Speed range is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X275SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X275SH replacement — usually within 7-8 hours.