This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X310S, 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 SI125X310S
The AirTAC SI125 Standard Cylinder SI125X310S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 310mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X310S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke310 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X310S
- 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 SI125X310S
The AirTAC SI125X310S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 310 mm stroke. It delivers a push force of 6136 N at 0.5 MPa and features a G1/2 air port. AirTAC replaced this legacy unit with the SAI125X310S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and porting.
The SAI replacement introduces an upgraded piston seal utilizing two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also adds SAIL and BSAI lock variants absent from the SI line. This -S SKU includes a piston magnet for CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X310S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X310S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X310S |
| Bore size | Ø125 mm |
| Stroke | 310 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 SAI125X310S 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 SAI125X310S 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 SI125X310S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×310 | 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 SI125X310S Is Used
Heavy Press Clamping
Secures large automotive castings during machining, utilizing the 6136 N push force at 0.5 MPa to hold components rigidly against cutting loads.
Pallet Lift Gates
Actuates heavy loading dock diverter gates, where the 313 kg vertical lift capacity handles substantial weighted platforms safely.
Bulk Material Diversion
Drives large-scale package routing arms on high-throughput sorting lines, relying on the 30-500 mm/s speed range for controlled transitions.
Replacing the Airtac SI125 Standard Cylinder SI125X310S with the SAI125X310S
To replace the SI125X310S, order the SAI125X310S and verify your ISO 15552 mounting interface, G1/2 port threads (PT/G/NPT), and M27x2 rod-end connections. The 310 mm stroke requires external guides to prevent rod bending under side loads. If sizing up or down, note the 100 mm bore provides 3927 N push at 0.5 MPa, while the 160 mm bore offers 10053 N. Because this is a 310 mm stroke, ensure adequate external guiding to manage deflection. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external pilot check valve, or specify the SAIL or BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X310S
- ✓ 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 SI125X310S FAQ
Yes, the AirTAC SI125X310S is discontinued. The direct replacement is the SAI125X310S. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 310 mm stroke, output force, G1/2 port, and mounting accessories.
This 125 mm bore cylinder uses a G1/2 air port. The thrust 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 maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X310S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X310S replacement — usually within 7-8 hours.