This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX500S, 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 SI125BX500S
The AirTAC SI125 Standard Cylinder SI125BX500S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 500mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX500S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke500 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX500S
- 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 SI125BX500S
The AirTAC SI125BX500S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 500 mm stroke. It delivers 6136 N push force at 0.5 MPa and features a SUS304 stainless piston rod for corrosion resistance. AirTAC replaced this legacy unit with the SAI125BX500S, a direct upgrade sharing the exact ISO 15552 mounting interface, G1/2 port, and M27x2 rod thread.
The SAI replacement retains all ratings but adds an upgraded piston seal using two Y-shaped one-way elements for lower start-up pressure and longer life. The original -S magnet supports CS1-B/DS1-B sensors, while the SAI family introduces SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI125 Standard Cylinder SI125BX500S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX500S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX500S |
| Bore size | Ø125 mm |
| Stroke | 500 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 SAI125BX500S 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 SAI125BX500S 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 SI125BX500S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×500 | 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 SI125BX500S Is Used
Heavy Pressing
Drives large stamping or forming presses requiring 6136 N push force at 0.5 MPa with stable 500 mm travel.
Pallet Handling
Actuates heavy load lifts and transfers where the 313 kg vertical lift capacity handles substantial material weights.
Corrosive Assembly
Ideal for washdown or chemical assembly lines utilizing the SUS304 stainless rod for maximum corrosion resistance.
Replacing the Airtac SI125 Standard Cylinder SI125BX500S with the SAI125BX500S
To replace the SI125BX500S, order the SAI125BX500S. Verify your ISO 15552 mounting fixtures, G1/2 air port, and M27x2 rod thread. The -S magnet maps to current AirTAC switches, while a no-S SKU cannot take a sensor. For sizing both ways: a 100 mm bore yields 3927 N push at 0.5 MPa, whereas a 160 mm bore yields 10053 N. A plain cylinder drifts on air loss, as the 40 mm adjustable cushion only decelerates; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 500 mm stroke, prevent rod bending by using an external guide to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX500S
- ✓ 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 SI125BX500S FAQ
Yes, the SI125BX500S is discontinued. The direct replacement is the SAI125BX500S. It shares the identical ISO 15552 mounting interface, 125 mm bore, 500 mm stroke, G1/2 port, and output force, fitting existing fixtures perfectly.
The 125 mm bore generates 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s, and the G1/2 port handles the required air volume.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX500S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX500S replacement — usually within 7-8 hours.