This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX150S, 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 SI125AX150S
The AirTAC SI125 Standard Cylinder SI125AX150S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 150mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX150S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke150 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX150S
- 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 SI125AX150S
The AirTAC SI125AX150S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 150mm stroke. Featuring a SUS420J2 stainless steel rod and a built-in magnet for CS1-B/DS1-B sensors, it delivers 6136 N push force at 0.5 MPa. AirTAC replaced this legacy unit with the SAI125AX150S, a direct sharing the same G1/2 port, M27x2 thread, and mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds lock variants (SAIL, BSAI) absent in the SI line. Note that air cushions only decelerate; use a lock valve for load holding.
Airtac SI125 Standard Cylinder SI125AX150S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX150S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX150S |
| Bore size | Ø125 mm |
| Stroke | 150 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 SAI125AX150S 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 SAI125AX150S 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 SI125AX150S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×150 | 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 SI125AX150S Is Used
Heavy Stamping
Drives large presses and stamping dies requiring high thrust, using the 6136 N push force at 0.5 MPa.
Pallet Handling
Indexes heavy loaded pallets along conveyors where the 125mm bore and robust 32mm rod handle side loads.
Clamp Fixtures
Secures large metal castings in machining centers, relying on the SUS420J2 rod for corrosion resistance.
Replacing the Airtac SI125 Standard Cylinder SI125AX150S with the SAI125AX150S
To replace the SI125AX150S, order the SAI125AX150S. Verify your ISO 15552 mounting interface, 150mm stroke, G1/2 port, and the -S magnet for legacy CS1-B/DS1-B sensors (the SAI uses current AirTAC switches). The SUS420J2 stainless rod resists corrosion. If sizing up or down, adjacent bores are 100mm (3927 N push @0.5 MPa) and 160mm (10053 N push @0.5 MPa). Because this plain cylinder drifts without live air, use an external rod lock or pilot check valve for load holding, or specify an SAIL/BSAI lock variant. With a 150mm stroke, ensure guide alignment to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX150S
- ✓ 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 SI125AX150S FAQ
Yes, the SI125AX150S is discontinued. The direct replacement is the SAI125AX150S. It shares the same ISO 15552 mounting interface, 125mm bore, 150mm stroke, output force, G1/2 port, and accessories, fitting directly into existing fixtures.
The 125mm bore features a G1/2 air port. 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 max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX150S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX150S replacement — usually within 7-8 hours.