This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X1250SFTC, 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 SI125X1250SFTC
The AirTAC SI125 Standard Cylinder SI125X1250SFTC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 1250mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X1250SFTC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke1250 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X1250SFTC
- 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 SI125X1250SFTC
The AirTAC SI125X1250SFTC is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 1250mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. The direct replacement is the SAI125X1250SFTC, matching the exact bore, stroke, force, port and FTC trunnion mount for a seamless fixture swap.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The original SI magnet works with CS1-B/DS1-B sensors, while SAIL lock and BSAI clamp-lock variants cover load-holding needs the base SI lacked.
Airtac SI125 Standard Cylinder SI125X1250SFTC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X1250SFTC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X1250SFTC |
| Bore size | Ø125 mm |
| Stroke | 1250 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 SAI125X1250SFTC 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 SAI125X1250SFTC 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 SI125X1250SFTC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×1250 | 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 SI125X1250SFTC Is Used
Large Press Demolding
Drives heavy molds in automotive stamping lines where the 125mm bore and 1250mm stroke clear deep draw depths.
Pallet Transfer Pusher
Shifts loaded pallets between roller sections, using the 6136N thrust to overcome high breakaway friction.
High-Bay Extraction Arm
Extends deep into storage racks to retrieve heavy totes, requiring external guides to manage the long 1.25m rod extension.
Replacing the Airtac SI125 Standard Cylinder SI125X1250SFTC with the SAI125X1250SFTC
To replace the SI125X1250SFTC, order the SAI125X1250SFTC. Verify the ISO 15552 FTC trunnion interface, 125mm bore, 1250mm stroke, G1/2 port (PT/G/NPT thread), M27x2 rod thread, and the -S magnet for CS1-B/DS1-B switches. Sizing up or down: a 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore yields 10053N. Note that a plain cylinder drifts without live air; use an external rod lock or pilot check valve for load holding. Because 1250mm exceeds 300mm, add external guides to prevent rod bending and side-load damage. Speed is 30-500mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X1250SFTC
- ✓ 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 SI125X1250SFTC FAQ
Yes, the SI125X1250SFTC is discontinued. The direct replacement is the SAI125X1250SFTC. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 125mm bore, 1250mm stroke, G1/2 port, force output, and FTC trunnion mount.
The bore is 125mm with a G1/2 air port and M27x2 rod thread. Forces are 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical max of 1251kgf at 1.0MPa. Operating speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X1250SFTC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X1250SFTC replacement — usually within 7-8 hours.