This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X70SFA, 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 SI125X70SFA
The AirTAC Airtac SI125 Standard Cylinder SI125X70SFA 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 SAI125X70SFA, 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 → SAI125X70SFA
- 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 SI125X70SFA
The AirTAC SI125X70SFA is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 70 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125X70SFA, a direct upgrade retaining the exact FA flange mount, M27x2 rod thread, and 40 mm cushions.
The SAI successor features an upgraded piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. For demanding thermal environments, Viton H seals expand the operating range up to 150 C. The built-in magnet (-S) supports legacy CS1-B/DS1-B sensors, while the SAI family introduces SAIL and BSAI lock variants absent in the original SI line.
Airtac SI125 Standard Cylinder SI125X70SFA Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X70SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X70SFA |
| 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 SAI125X70SFA 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 SAI125X70SFA 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 SI125X70SFA
| 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 SI125X70SFA Is Used
Heavy Press Clamping
Generates 6136 N at 0.5 MPa to secure large metal castings or heavy assemblies during machining and press operations.
Industrial Forming Press
Provides the robust linear force required for stamping, bending, or forming thick-gauge materials in automated lines.
Pallet Lift Actuation
Drives heavy-duty lifting mechanisms in packaging and logistics, safely handling vertical loads up to 313 kg.
Replacing the Airtac SI125 Standard Cylinder SI125X70SFA with the SAI125X70SFA
To replace the SI125X70SFA, order the SAI125X70SFA. It is dimensionally interchangeable per the ISO 15552 mounting interface, matching the 125 mm bore, 70 mm stroke, G1/2 port, and FA flange. Confirm your thread standard (PT, G, or NPT) and retain the existing magnet for current AirTAC switches. For sizing context, stepping down to an 80 mm bore yields 2513 N push at 0.5 MPa, while this 125 mm bore provides 8590 N at 0.7 MPa. Note that a standard cylinder drifts without live air; the cushion only decelerates at stroke end. For load holding on air loss, specify an external pilot check valve or the SAIL/BSAI lock variant. At 70 mm stroke, side-load risks are minimal, but ensure axial alignment to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X70SFA
- ✓ 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 SI125X70SFA FAQ
Yes, the SI125X70SFA is discontinued. The direct replacement is the SAI125X70SFA. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 70 mm stroke, G1/2 port, FA flange mount, and output force.
The bore is 125 mm with a G1/2 air port. Force output is 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. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X70SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X70SFA replacement — usually within 7-8 hours.