This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X300, 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 SI125X300
The AirTAC SI125 Standard Cylinder SI125X300 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 300mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X300, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke300 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X300
- 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 SI125X300
The AirTAC SI125X300 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 300 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. Because this legacy unit lacks the -S magnet suffix, it cannot accept a position sensor.
Order the direct replacement SAI125X300 instead. It shares the exact ISO 15552 mounting interface, M27x2 rod thread, and 1251 kgf max force. The SAI upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure.
Airtac SI125 Standard Cylinder SI125X300 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X300 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X300 |
| Bore size | Ø125 mm |
| Stroke | 300 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 SAI125X300 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 SAI125X300 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 SI125X300
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×300 | 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 SI125X300 Is Used
Heavy Stamping Press
Drives large dies and heavy platens in metal forming, utilizing the 6136 N push force at 0.5 MPa to shape thick steel blanks reliably.
Pallet Handling Lift
Actuates robust lifting arms in automated warehouses, moving loaded pallets where the 313 kg vertical lift capacity handles substantial weight.
Large Mold Clamping
Secures oversized injection molds on the production floor, providing the rigid 125 mm bore holding power required during high-pressure cycles.
Replacing the Airtac SI125 Standard Cylinder SI125X300 with the SAI125X300
To replace the SI125X300, specify the SAI125X300 keeping the 125 mm bore, 300 mm stroke, and G1/2 port. Confirm your mounting accessory (LB, FA, TC, etc.) and thread standard (PT, G, NPT). Since this SKU has no -S magnet, it cannot hold a sensor; the SAI family uses current AirTAC switches if sensing is needed. At 0.5 MPa it pushes 6136 N and pulls 5734 N; if undersized, the 160 mm bore offers 10053 N. Note that at 300 mm stroke, external guides are recommended to prevent rod bending from side loads. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X300
- ✓ 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 SI125X300 FAQ
Yes, the SI125X300 is discontinued. The direct replacement is the AirTAC SAI125X300. It shares the same ISO 15552 mounting interface, 125 mm bore, 300 mm stroke, output force, G1/2 port, and accessories, fitting directly into existing fixtures.
At 0.5 MPa it pushes 6136 N and pulls 5734 N. At 0.7 MPa it pushes 8590 N, and 11045 N at 0.9 MPa. The theoretical max force is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X300
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X300 replacement — usually within 7-8 hours.