This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X5, 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 SI125X5
The AirTAC Airtac SI125 Standard Cylinder SI125X5 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 5mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X5, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke5 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X5
- 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 SI125X5
The AirTAC SI125X5 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 5 mm stroke, delivering 6136 N push force at 0.5 MPa via its G1/2 port. AirTAC replaced it with the SAI125X5, a direct alternative retaining the exact interface, M27x2 rod thread, and 40 mm cushions. This non-magnetic SKU lacks a sensor groove switch and cannot take a CS1-B/DS1-B sensor.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. If high heat is expected, Viton H seals raise the operating range to 150 C.
Airtac SI125 Standard Cylinder SI125X5 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X5 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X5 |
| Bore size | Ø125 mm |
| Stroke | 5 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 SAI125X5 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 SAI125X5 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 SI125X5
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×5 | 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 SI125X5 Is Used
Heavy-Duty Clamping
Ideal for short-stroke, high-force clamping of large steel plates in machining centers, using its 6136 N push force at 0.5 MPa to secure parts rigidly.
Press Fit Operations
Provides reliable 5 mm pressing force for inserting heavy bearings or bushings into housings on automated assembly lines without requiring full stroke closure.
Stub Ejection
Functions as a compact, high-power ejection piston to knock heavy forged parts out of molds, where a 125 mm bore delivers immediate impact within 5 mm.
Replacing the Airtac SI125 Standard Cylinder SI125X5 with the SAI125X5
To replace this SI125X5, order the SAI125X5 and confirm the ISO 15552 mounting interface, 125 mm bore, 5 mm stroke, and G1/2 port (PT/G/NPT thread options). Keep the same mounting accessory (LB, FA, TC, etc.) and note this non-S SKU cannot accept a sensor. Because the 5 mm stroke is extremely short, side-load risks are minimal, but ensure the rod-end thread (M27x2) aligns with your fixture. If you need to hold a load securely without live air, remember the cushion only decelerates; use an external pilot check valve or switch to the SAIL or BSAI lock variant. To size both ways, dropping to an 80 mm bore yields 2513 N push at 0.5 MPa, while pushing to 0.7 MPa on this 125 mm bore yields 8590 N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X5
- ✓ 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 SI125X5 FAQ
Yes, the AirTAC SI125X5 is discontinued. The direct replacement is the SAI125X5. It is a true ISO 15552 profile cylinder that matches the 125 mm bore, 5 mm stroke, 6136 N force, G1/2 port, and mounting interface, so it drops directly into existing fixtures.
This 125 mm bore cylinder features a G1/2 air port and an M27x2 rod thread. The force output is 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. It operates at 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X5
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X5 replacement — usually within 7-8 hours.