This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX15S, 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 SI125BX15S
The AirTAC SI125 Standard Cylinder SI125BX15S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 15mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX15S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke15 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX15S
- 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 SI125BX15S
The AirTAC SI125BX15S is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore, a 15 mm nonstandard stroke, and a SUS304 stainless steel rod. It delivers 6136 N push and 5734 N pull at 0.5 MPa through its G1/2 port. The direct replacement is the SAI125BX15S, which retains the identical ISO 15552 mounting interface, bore, stroke, output force, and port size for seamless fixture integration.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. This -S model includes a piston magnet for legacy CS1-B/DS1-B sensors, and the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI125 Standard Cylinder SI125BX15S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX15S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX15S |
| Bore size | Ø125 mm |
| Stroke | 15 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 SAI125BX15S 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 SAI125BX15S 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 SI125BX15S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×15 | 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 SI125BX15S Is Used
Short-Stroke Clamping
Ideal for high-force, short-travel clamping tasks where the 6136 N push force secures heavy metal components during machining, utilizing the SUS304 rod for corrosion resistance.
Heavy Pressing Operations
Provides reliable downward pressing force for assembly pins or rivets, where the 15 mm nonstandard stroke offers precise, controlled impact without overtravel.
Stainless Rod Ejection
Suitable for ejecting parts in humid or washdown environments, leveraging the SUS304 rod and robust 5734 N pull force to reliably strip components from molds.
Replacing the Airtac SI125 Standard Cylinder SI125BX15S with the SAI125BX15S
To replace the SI125BX15S, order the SAI125BX15S. Verify your ISO 15552 mounting accessories (LB, FA, TC, etc.), the G1/2 port thread (PT, G, or NPT), and the -S magnet requirement. The SAI uses current AirTAC switches instead of the legacy CS1-B/DS1-B. If sizing alternatives, a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. Note that 15 mm is a nonstandard stroke. Because this is a plain cylinder, it cannot hold a load without live air; the 40 mm adjustable cushion only decelerates. For load-holding, use an external pilot check valve, rod lock, or the SAIL/BSAI variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX15S
- ✓ 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 SI125BX15S FAQ
Yes, the AirTAC SI125BX15S is discontinued. The direct replacement is the SAI125BX15S. It is dimensionally interchangeable per ISO 15552, offering the same bore, stroke, force, G1/2 port, and mounting interface.
The 125 mm bore cylinder operates at 30-500 mm/s. It generates 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. It uses a G1/2 port.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX15S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX15S replacement — usually within 7-8 hours.