This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X20H, 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 SI125X20H
The AirTAC SI125 Standard Cylinder SI125X20H is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 20mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X20H, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke20 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X20H
- 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 SI125X20H
The AirTAC SI125X20H is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 20 mm stroke. It delivers 6136 N push force at 0.5 MPa, features a G1/2 port, and uses a Viton H seal for 0-150 C high-temp environments. The direct replacement is the SAI125X20H, matching the interface, force, and port exactly.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and longevity. Without a -S suffix, this SKU cannot take a magnetic sensor. For load holding, note the cushion only decelerates; use an external rod lock or SAIL/BSAI variant.
Airtac SI125 Standard Cylinder SI125X20H Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X20H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X20H |
| Bore size | Ø125 mm |
| Stroke | 20 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 SAI125X20H 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 SAI125X20H 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 SI125X20H
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×20 | 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 SI125X20H Is Used
High-Temp Pressing
Applies 6136 N of push force at 0.5 MPa for stamping or clamping parts in heated industrial environments up to 150 C using the Viton H seal.
Heavy Duty Ejection
Short 20 mm stroke delivers rapid, high-force ejection of molded or fabricated components from machinery without occupying excessive axial space.
Industrial Spot Welding
Provides the robust 125 mm bore clamping pressure required to hold heavy steel assemblies firmly in place during automated resistance welding cycles.
Replacing the Airtac SI125 Standard Cylinder SI125X20H with the SAI125X20H
To replace the SI125X20H, order the SAI125X20H. Verify the ISO 15552 mounting interface, 125 mm bore, 20 mm stroke, G1/2 port, and Viton H high-temperature seal. Because this SKU lacks the -S magnet, it cannot accept legacy CS1-B/DS1-B sensors. For sizing alternatives, the 100 mm bore offers 3927 N push at 0.5 MPa, while the 160 mm bore provides 10053 N. At 0.7 MPa, this 125 mm unit pushes 8590 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for holding loads use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X20H
- ✓ 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 SI125X20H FAQ
Yes, the SI125X20H is discontinued. The direct replacement is the SAI125X20H. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 20 mm stroke, G1/2 port, and mounting fixtures.
The G1/2 port bore delivers 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 maximum theoretical force of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X20H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X20H replacement — usually within 7-8 hours.