This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X270SN, 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 SI125X270SN
The AirTAC SI125 Standard Cylinder SI125X270SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 270mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X270SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke270 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X270SN
- 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 SI125X270SN
The AirTAC SI125X270SN is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 270mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. The direct replacement is the SAI125X270SN, retaining the exact interface, force, and mounting.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. The NBR seal handles -20 to +70C; Viton H extends this to 150C. The built-in magnet pairs with legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X270SN Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X270SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X270SN |
| Bore size | Ø125 mm |
| Stroke | 270 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 SAI125X270SN 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 SAI125X270SN 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 SI125X270SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×270 | 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 SI125X270SN Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136N push force to maintain rigid fixture clamping at 0.5 MPa.
Pallet Load Shift
Pushes heavy loaded pallets laterally onto transfer conveyors, where the 270mm stroke accommodates standard pallet widths safely.
Injection Mold Ejection
Drives the ejection plate of mid-size plastic injection molds, benefiting from the adjustable 40mm air cushions to decelerate heavy tooling.
Replacing the Airtac SI125 Standard Cylinder SI125X270SN with the SAI125X270SN
To replace the SI125X270SN, order the SAI125X270SN direct, confirming the ISO 15552 mounting interface, 125mm bore, 270mm stroke, G1/2 port, and NBR seals. It includes a magnet for current AirTAC switches (replacing legacy CS1-B/DS1-B). For sizing, a neighboring 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore yields 10053N. At 270mm stroke, ensure guide alignment to prevent rod-bending side loads. This plain cylinder does not hold load without air; use an external pilot check valve or the SAIL/BSAI lock variant for hold.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X270SN
- ✓ 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 SI125X270SN FAQ
Yes, the AirTAC SI125X270SN is discontinued. The direct replacement is the SAI125X270SN. It is dimensionally interchangeable per ISO 15552, offering the same 125mm bore, 270mm stroke, G1/2 port, and mounting interface.
This double-acting cylinder features a G1/2 air port and M27x2 rod thread. Force output is 6136N push and 5734N pull at 0.5 MPa, 8590N push at 0.7 MPa, 11045N push at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X270SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X270SN replacement — usually within 7-8 hours.