This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX210S, 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 SI125AX210S
The AirTAC SI125 Standard Cylinder SI125AX210S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 210mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX210S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke210 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX210S
- 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 SI125AX210S
The AirTAC SI125AX210S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 210 mm stroke. It delivers 6136 N push force at 0.5 MPa, featuring a SUS420J2 stainless piston rod (-A) and a built-in magnet (-S) for CS1-B/DS1-B sensors. The direct replacement is the SAI125AX210S, which shares the same G1/2 port, M27x2 thread, and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI125 Standard Cylinder SI125AX210S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX210S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX210S |
| Bore size | Ø125 mm |
| Stroke | 210 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 SAI125AX210S 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 SAI125AX210S 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 SI125AX210S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×210 | 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 SI125AX210S Is Used
Heavy-Duty Pressing
Drives large stamping or forming fixtures requiring 6136 N of push force at 0.5 MPa with stable ISO 15552 mounting.
Pallet Handling
Shifts heavy loaded pallets along conveyors, utilizing the 125 mm bore and 210 mm stroke for robust actuation.
Automated Assembly
Secures and positions large fabricated components during multi-stage automated machinery assembly processes.
Replacing the Airtac SI125 Standard Cylinder SI125AX210S with the SAI125AX210S
To replace the SI125AX210S, order the SAI125AX210S. Verify the ISO 15552 mounting interface, 125 mm bore, 210 mm stroke, G1/2 port (PT/G/NPT), and the -S magnet for current AirTAC switches. Sizing up or down: a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. Because this is a 210 mm stroke, ensure adequate guide support to prevent rod bending under side loads. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX210S
- ✓ 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 SI125AX210S FAQ
Yes, the SI125AX210S is discontinued. The direct replacement is the SAI125AX210S. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 210 mm stroke, output force, G1/2 port, and mounting accessories.
It features a G1/2 port. The force ratings are: 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N push at 0.9 MPa, and a theoretical maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX210S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX210S replacement — usually within 7-8 hours.