This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX185S, 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 SI125BX185S
The AirTAC SI125 Standard Cylinder SI125BX185S 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 SAI125BX185S, 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 → SAI125BX185S
- 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 SI125BX185S
The AirTAC SI125BX185S is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore, 185mm stroke, and a SUS304 stainless steel piston rod. Generating 6136N push force at 0.5MPa, it is replaced by the direct replacement SAI125BX185S. This upgrade retains the exact G1/2 port, M27x2 thread, and mounting interface, fitting existing fixtures perfectly.
The SAI replacement introduces an upgraded piston seal with two Y-shaped elements for low start-up pressure and long life. The -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL and BSAI lock variants absent in the SI line.
Airtac SI125 Standard Cylinder SI125BX185S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX185S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX185S |
| 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 SAI125BX185S 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 SAI125BX185S 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 SI125BX185S
| 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 SI125BX185S Is Used
Heavy-Duty Pressing
Applies the 8590N push force at 0.7MPa for securing heavy components in automated assembly lines.
Stainless Rod Clamping
Leverages the SUS304 rod for corrosion resistance in washdown clamping and forming environments.
Replacing the Airtac SI125 Standard Cylinder SI125BX185S with the SAI125BX185S
To replace the SI125BX185S, order the SAI125BX185S, confirming the ISO 15552 interface, 125mm bore, 185mm stroke, G1/2 port, and mounting accessory. The -B rod is SUS304 stainless steel, and the -S magnet works with legacy CS1-B/DS1-B switches (the SAI uses current AirTAC switches). For sizing both ways: a 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore yields 10053N. Note that a plain cylinder drifts on air loss, as the cushion only decelerates; use an external rod lock or pilot check valve for load holding. The SAIL or BSAI lock variants are alternatives if needed. Operating speed is 30-500mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX185S
- ✓ 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 SI125BX185S FAQ
Yes, the SI125BX185S is discontinued. The direct replacement is the SAI125BX185S, which shares the same ISO 15552 mounting interface, 125mm bore, 185mm stroke, force, and G1/2 port.
It has a G1/2 port. Force ratings are 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical max of 1251kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX185S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX185S replacement — usually within 7-8 hours.