This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X300FTC, 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 SI125X300FTC
The AirTAC SI125 Standard Cylinder SI125X300FTC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 300mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X300FTC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke300 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X300FTC
- 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 SI125X300FTC
The AirTAC SI125X300FTC is a discontinued double-acting ISO 15552 profile cylinder with an FTC trunnion mount, delivering 6136 N push force at 0.5 MPa. AirTAC replaced it with the SAI125X300FTC, a direct sharing the same 125 mm bore, 300 mm stroke, G1/2 port, and ISO 15552 mounting interface.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this SKU lacks a magnet (-S), so it cannot accept CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X300FTC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X300FTC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X300FTC |
| Bore size | Ø125 mm |
| Stroke | 300 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 SAI125X300FTC 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 SAI125X300FTC 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 SI125X300FTC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×300 | 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 SI125X300FTC Is Used
Heavy Pressing
Drives large stamping or forming fixtures requiring 6136 N of push force at 0.5 MPa.
Pallet Diverting
Shifts heavy loaded pallets laterally using the FTC trunnion mount to handle 300 mm strokes.
Replacing the Airtac SI125 Standard Cylinder SI125X300FTC with the SAI125X300FTC
To replace the SI125X300FTC, order the SAI125X300FTC to retain the exact ISO 15552 FTC trunnion interface, 125 mm bore, 300 mm stroke, and G1/2 port. Because this is a 300 mm stroke, use external guides to prevent rod bending and side-load damage. If downsizing, a 100 mm bore yields 3927 N at 0.5 MPa; if upsizing, a 160 mm bore provides 10053 N. This plain cylinder does not hold load on air loss—use the SAIL lock or BSAI clamp-lock variant, or an external pilot check valve. Speed is 30-500 mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X300FTC
- ✓ 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 SI125X300FTC FAQ
Yes, the SI125X300FTC is discontinued. The direct replacement is the SAI125X300FTC, which matches the ISO 15552 FTC mounting interface, 125 mm bore, 300 mm stroke, force, and G1/2 port.
It has a G1/2 port. Force outputs 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 maximum theoretical force of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X300FTC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X300FTC replacement — usually within 7-8 hours.