This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX300SN, 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 SI125BX300SN
The AirTAC SI125 Standard Cylinder SI125BX300SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 300mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX300SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke300 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX300SN
- 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 SI125BX300SN
The AirTAC SI125BX300SN is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore, 300 mm stroke, and a SUS304 stainless steel rod. It delivers 6136 N push force at 0.5 MPa. The direct replacement is the SAI125BX300SN, retaining 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. This -SN variant uses NBR seals (-20 to +70 C) and a piston magnet for CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125BX300SN Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX300SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX300SN |
| Bore size | Ø125 mm |
| Stroke | 300 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 SAI125BX300SN 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 SAI125BX300SN 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 SI125BX300SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×300 | 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 SI125BX300SN Is Used
Heavy Press Forming
Applies the 6136 N push force at 0.5 MPa for stamping and forming rigid sheet metal components.
Pallet Lift Stations
Lifts loaded pallets up to the 313 kg vertical limit, utilizing the 300 mm stroke for elevation changes.
Large Clamp Fixtures
Secures heavy workpieces during machining, relying on the stable 125 mm bore and SUS304 rod.
Replacing the Airtac SI125 Standard Cylinder SI125BX300SN with the SAI125BX300SN
To replace the SI125BX300SN, order the SAI125BX300SN to match the 125 mm bore, 300 mm stroke, G1/2 port, and ISO 15552 mounting. If downsizing, a 100 mm bore yields 3927 N push at 0.5 MPa; if upsizing, a 160 mm bore provides 10053 N. For this 300 mm stroke, use an external guide to prevent rod bending and side loads. The cushion only decelerates; for load holding on air loss, use an external rod lock or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX300SN
- ✓ 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 SI125BX300SN FAQ
Yes, the SI125BX300SN is discontinued. The direct replacement is the SAI125BX300SN. It is dimensionally interchangeable per ISO 15552, matching the bore, stroke, force, G1/2 port, and mounting fixtures.
It has 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 SAI125BX300SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX300SN replacement — usually within 7-8 hours.