This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X500SFTC, 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 SI125X500SFTC
The AirTAC SI125 Standard Cylinder SI125X500SFTC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 500mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X500SFTC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke500 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X500SFTC
- 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 SI125X500SFTC
The AirTAC SI125X500SFTC is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 500 mm stroke. It delivers 6136 N push force at 0.5 MPa, utilizing a G1/2 port and M27x2 rod thread. The direct replacement is the SAI125X500SFTC, which matches the original FTC trunnion mounting, bore, stroke, and output force.
The SAI upgrade introduces a refined piston seal featuring two Y-shaped one-way elements for low start-up pressure and extended life. The original SI uses a TPU seal rated for -20 to +70 C, though Viton H options raise this to 150 C, and its integrated magnet supports CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X500SFTC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X500SFTC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X500SFTC |
| Bore size | Ø125 mm |
| Stroke | 500 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 SAI125X500SFTC 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 SAI125X500SFTC 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 SI125X500SFTC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×500 | 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 SI125X500SFTC Is Used
Heavy Stamp Pressing
Ideal for driving large stamping dies requiring 6136 N of push force at 0.5 MPa, with FTC trunnion mounting handling pivot stresses.
Bulk Material Diversion
Actuates heavy-duty diverter arms on high-capacity lines, relying on the 40 mm adjustable air cushions to decelerate the 125 mm bore smoothly.
Replacing the Airtac SI125 Standard Cylinder SI125X500SFTC with the SAI125X500SFTC
To replace the SI125X500SFTC, order the SAI125X500SFTC. Verify that the ISO 15552 mounting interface matches your FTC trunnion accessory, and confirm the G1/2 port, M27x2 rod thread, 500 mm stroke, and the -S magnet for CS1-B/DS1-B legacy sensors (the SAI uses current AirTAC switches). If sizing alternatives, neighboring bores or the 8590 N push force at 0.7 MPa can be evaluated. Because this is a 500 mm stroke, external guides are recommended to prevent rod bending and side-load damage. A plain cylinder drifts without live air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X500SFTC
- ✓ 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 SI125X500SFTC FAQ
Yes, the SI125X500SFTC is discontinued. The direct replacement is the SAI125X500SFTC. It is dimensionally interchangeable per ISO 15552, matching the bore, stroke, force, G1/2 port, and FTC trunnion mounting.
It has a G1/2 port. The force 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. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X500SFTC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X500SFTC replacement — usually within 7-8 hours.