This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X300TC, 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 SI125X300TC
The AirTAC SI125 Standard Cylinder SI125X300TC 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 SAI125X300TC, 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 → SAI125X300TC
- 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 SI125X300TC
The AirTAC SI125X300TC is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 300 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125X300TC, matching the exact TC trunnion mount, M27x2 rod thread, and output force.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. Note this SKU lacks a magnet, so it cannot accept CS1-B/DS1-B sensors. If high temps are needed, a Viton H seal option extends range to 150 C.
Airtac SI125 Standard Cylinder SI125X300TC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X300TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X300TC |
| 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 SAI125X300TC 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 SAI125X300TC 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 SI125X300TC
| 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 SI125X300TC Is Used
Heavy Press Clamping
Secures large steel plates in an assembly press, utilizing the 6136 N push force at 0.5 MPa to hold components firmly during heavy-duty machining or fastening operations.
Bulk Material Diversion
Pivots heavy diverter gates on high-capacity packaging lines, using the 300 mm stroke to reroute dense product flows without requiring external air-holding locks during transitions.
Replacing the Airtac SI125 Standard Cylinder SI125X300TC with the SAI125X300TC
To replace the SI125X300TC, order the SAI125X300TC. Confirm the ISO 15552 interface, 125 mm bore, 300 mm stroke, G1/2 port (PT/G/NPT), and TC trunnion mounting. Because this SKU has no -S magnet, it cannot support position sensing; order a magnet-equipped SAI if you need switches. For sizing, the 125 mm bore yields 6136 N push at 0.5 MPa (1251 kgf max at 1.0 MPa); step down to an 80 mm bore (2513 N push) for lighter loads, or up to 160 mm (10053 N) for heavier. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for held loads. At 300 mm stroke, prevent rod bending by guiding the load externally to avoid side-load damage. Speed is 30-500 mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X300TC
- ✓ 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 SI125X300TC FAQ
Yes, the SI125X300TC is discontinued. The direct replacement is the SAI125X300TC. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 300 mm stroke, G1/2 port, TC trunnion mount, and output force. The SAI simply upgrades the piston seal to two Y-shaped one-way elements for longer life and lower start-up pressure.
The 125 mm bore features a G1/2 air port and an M27x2 rod thread. Force output is 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, and 11045 N push at 0.9 MPa. The theoretical maximum force is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X300TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X300TC replacement — usually within 7-8 hours.