This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X70SN, 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 SI125X70SN
The AirTAC SI125 Standard Cylinder SI125X70SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 70mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X70SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke70 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X70SN
- 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 SI125X70SN
The AirTAC SI125X70SN is a discontinued double-acting ISO 15552 profile cylinder. It delivers 6136 N push force at 0.5 MPa through a 125 mm bore, 70 mm stroke, and G1/2 port. The direct replacement is the SAI125X70SN, matching the bore, stroke, output force, port size, and ISO 15552 mounting interface for existing fixtures.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This SI unit includes a -S magnet for legacy CS1-B/DS1-B sensors, and an -N NBR seal rated for -20 to +70 C (Viton H raises this to 150 C). For load holding, note the cushion only decelerates; use the SAIL or BSAI lock variants.
Airtac SI125 Standard Cylinder SI125X70SN Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X70SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X70SN |
| Bore size | Ø125 mm |
| Stroke | 70 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 SAI125X70SN 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 SAI125X70SN 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 SI125X70SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×70 | 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 SI125X70SN Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136 N push force at 0.5 MPa to hold components rigidly against the tooling bed.
Pallet Diverting
Actuates heavy-duty routing gates on automated assembly lines, providing reliable 70 mm stroke movements to redirect loaded pallets at high speeds.
Replacing the Airtac SI125 Standard Cylinder SI125X70SN with the SAI125X70SN
To replace the SI125X70SN, order the SAI125X70SN. Confirm the ISO 15552 mounting interface (LB, FA, CA, TC, etc.), the G1/2 port, the M27x2 rod thread, and the -S magnet for current AirTAC switches. Sizing both ways: a 100 mm bore gives 3927 N push at 0.5 MPa, while a 160 mm bore gives 10053 N. This 125 mm bore yields 6136 N push and 5734 N pull at 0.5 MPa, with a max 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s. The plain cylinder does not hold load without live air; for drop prevention use the SAIL lock, BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X70SN
- ✓ 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 SI125X70SN FAQ
Yes, the AirTAC SI125X70SN is discontinued. The direct replacement is the SAI125X70SN. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 70 mm stroke, force, G1/2 port, and mounting interface.
This double-acting cylinder features a G1/2 port. The thrust 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 SAI125X70SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X70SN replacement — usually within 7-8 hours.