This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X345TC, 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 SI125X345TC
The AirTAC SI125 Standard Cylinder SI125X345TC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 345mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X345TC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke345 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X345TC
- 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 SI125X345TC
The AirTAC SI125X345TC is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 345 mm stroke. It delivers 6136 N push force at 0.5 MPa through a G1/2 port. The direct replacement is the SAI125X345TC, matching the exact TC trunnion mount, M27x2 rod thread, and 40 mm cushions.
Upgrading to the SAI brings an improved piston seal with two Y-shaped elements for lower start-up pressure. Without a -S magnet, this SKU cannot accept a sensor.
Airtac SI125 Standard Cylinder SI125X345TC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X345TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X345TC |
| Bore size | Ø125 mm |
| Stroke | 345 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 SAI125X345TC 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 SAI125X345TC 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 SI125X345TC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×345 | 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 SI125X345TC Is Used
Heavy Press Operations
Drives large platens requiring up to 6136 N of thrust at 0.5 MPa, utilizing the 125 mm bore for high-force stamping and forming tasks.
Bulk Material Diversion
Actuates heavy-duty diverter arms on packaging lines, with the 345 mm stroke providing the reach needed to redirect large palletized goods.
Replacing the Airtac SI125 Standard Cylinder SI125X345TC with the SAI125X345TC
To replace the SI125X345TC, order the SAI125X345TC. It is dimensionally interchangeable per the ISO 15552 mounting interface, preserving the TC trunnion mount, 125 mm bore, 345 mm stroke, and G1/2 port. Because this SKU lacks a magnet, it cannot take a CS1-B or DS1-B sensor; if sensing is needed, switch to an -S variant using current AirTAC switches. If sizing down, a 100 mm bore gives 3927 N push at 0.5 MPa; sizing up to 160 mm provides 10053 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. At 345 mm, prevent rod bending by guiding the load externally to avoid side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X345TC
- ✓ 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 SI125X345TC FAQ
Yes, the SI125X345TC is discontinued. The direct replacement is the SAI125X345TC. It is dimensionally interchangeable per ISO 15552, retaining the same TC mount, 125 mm bore, 345 mm stroke, force, and G1/2 port.
It features 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 SAI125X345TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X345TC replacement — usually within 7-8 hours.