This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX185S, 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 SI125AX185S
The AirTAC SI125 Standard Cylinder SI125AX185S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 185mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX185S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke185 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX185S
- 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 SI125AX185S
The AirTAC SI125AX185S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore, 185 mm stroke, and a SUS420J2 stainless steel rod. Delivering 6136 N push force at 0.5 MPa, it is replaced by the SAI125AX185S. This direct upgrade matches the G1/2 port, M27x2 thread, and ISO 15552 mounting interface.
The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure. For load holding, note that the cushion only decelerates; use an external rod lock or the SAIL lock variant. The -S magnet works with CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125AX185S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX185S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX185S |
| Bore size | Ø125 mm |
| Stroke | 185 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 SAI125AX185S 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 SAI125AX185S 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 SI125AX185S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×185 | 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 SI125AX185S Is Used
Heavy Press Clamping
Secures large metal workpieces in machining centers, using the 6136 N thrust to hold parts firmly against cutting forces.
Pallet Positioning
Indexes loaded pallets on roller conveyors, providing the robust push force needed to overcome friction in heavy material handling.
Mold Ejection Systems
Ejects dense composite or metallic parts from molding tools, utilizing the 32 mm rod to withstand high ejection resistance.
Replacing the Airtac SI125 Standard Cylinder SI125AX185S with the SAI125AX185S
To replace the SI125AX185S, order the SAI125AX185S, confirming the ISO 15552 interface, 125 mm bore, 185 mm stroke, G1/2 port, and -S magnet. If downsizing, the 100 mm bore yields 3927 N push at 0.5 MPa; if upsizing, the 160 mm bore provides 10053 N. The standard speed is 30-500 mm/s. Because this is a 185 mm stroke, ensure your guide handles side loads to prevent rod bending. A plain cylinder drifts without air; for held loads, use a pilot check valve or the BSAI clamp-lock variant. The -A rod is SUS420J2 stainless steel.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX185S
- ✓ 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 SI125AX185S FAQ
Yes, the SI125AX185S is discontinued. The direct replacement is the SAI125AX185S. It shares the same ISO 15552 mounting interface, 125 mm bore, 185 mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
This 125 mm bore cylinder has a G1/2 air port. At 0.5 MPa it provides 6136 N push and 5734 pull force. At 0.7 MPa it pushes 8590 N, and at 0.9 MPa it pushes 11045 N. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX185S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX185S replacement — usually within 7-8 hours.