This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX325, 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 SI125BX325
The AirTAC SI125 Standard Cylinder SI125BX325 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 325mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX325, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke325 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX325
- 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 SI125BX325
The AirTAC SI125BX325 is a discontinued double-acting ISO 15552 profile cylinder featuring a SUS304 stainless piston rod and a 325 mm stroke. Delivering 6136 N push force at 0.5 MPa, it is replaced by the SAI125BX325. This direct successor shares the exact G1/2 port, M27x2 thread, and ISO 15552 mounting interface for seamless fixture integration.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and longevity. For this non-magnet SKU, position sensing is impossible. The SAI family also adds SAIL and BSAI lock variants absent from the SI line.
Airtac SI125 Standard Cylinder SI125BX325 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX325 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX325 |
| Bore size | Ø125 mm |
| Stroke | 325 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 SAI125BX325 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 SAI125BX325 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 SI125BX325
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×325 | 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 SI125BX325 Is Used
Heavy Stamping
Drives large presses and stamping dies requiring high thrust, utilizing the 6136 N push force at 0.5 MPa.
Pallet Handling
Indexes heavy pallets over the 325 mm stroke, relying on external guides to manage side loads safely.
Clamp Actuation
Secures large fabricated components during machining, benefiting from the SUS304 rod in humid environments.
Replacing the Airtac SI125 Standard Cylinder SI125BX325 with the SAI125BX325
To replace the SI125BX325, order the SAI125BX325 and verify the ISO 15552 mounting interface, G1/2 port, and M27x2 rod thread. Because this SKU lacks a magnet, it cannot accept a CS1-B/DS1-B sensor; choose an SAI variant with an -S suffix if sensing is required. The 325 mm stroke demands external guides to prevent rod bending under side loads. For sizing, the 100 mm bore yields 3927 N at 0.5 MPa, while the 160 mm bore provides 10053 N. Note that a plain cylinder drifts on air loss; for load holding, specify an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX325
- ✓ 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 SI125BX325 FAQ
Yes, the SI125BX325 is discontinued. The direct replacement is the SAI125BX325, which shares the same ISO 15552 mounting interface, 125 mm bore, 325 mm stroke, force, and G1/2 port.
It features a G1/2 port. The force ratings are: 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX325
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX325 replacement — usually within 7-8 hours.