This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X275TC, 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 SI125X275TC
The AirTAC SI125 Standard Cylinder SI125X275TC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 275mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X275TC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke275 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X275TC
- 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 SI125X275TC
The AirTAC SI125X275TC is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 275 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125X275TC, which matches the TC trunnion mount, M27x2 thread, and output force exactly.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This non-magnet SKU cannot take a sensor. For high heat, choose the Viton H seal option (0-150 C); for load holding, use the SAIL or BSAI lock variant.
Airtac SI125 Standard Cylinder SI125X275TC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X275TC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X275TC |
| Bore size | Ø125 mm |
| Stroke | 275 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 SAI125X275TC 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 SAI125X275TC 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 SI125X275TC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×275 | 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 SI125X275TC Is Used
Heavy Press Clamping
Secures large steel plates in machining centers, utilizing the 6136 N push force to hold workpieces firmly against vibration.
Automated Assembly Rams
Drives heavy-duty actuators and indexing pins in automated lines, relying on the 40 mm adjustable air cushions to absorb end-of-stroke impact.
Replacing the Airtac SI125 Standard Cylinder SI125X275TC with the SAI125X275TC
To replace the SI125X275TC, order the SAI125X275TC. Confirm the ISO 15552 TC trunnion interface, 125 mm bore, 275 mm stroke, G1/2 port (PT/G/NPT), and M27x2 rod thread. This non-S SKU lacks a magnet and cannot accept CS1-B/DS1-B sensors. For sizing both ways: a 100 mm bore gives 3927 N push at 0.5 MPa, while a 160 mm bore gives 10053 N. The 275 mm stroke is under the 1500 mm max, but for any stroke >=300 mm, use a guide to prevent rod bending. A plain cylinder drifts on air loss; for held loads, specify the SAIL lock or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X275TC
- ✓ 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 SI125X275TC FAQ
Yes, the SI125X275TC is discontinued. The direct replacement is the SAI125X275TC. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 275 mm stroke, G1/2 port, TC mounting, and output force.
The bore is 125 mm with a G1/2 air port and M27x2 rod thread. Force ratings are: push 6136 N and pull 5734 N at 0.5 MPa, push 8590 N at 0.7 MPa, push 11045 N at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X275TC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X275TC replacement — usually within 7-8 hours.