This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X315S, 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 SI125X315S
The AirTAC SI125 Standard Cylinder SI125X315S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 315mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X315S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke315 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X315S
- 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 SI125X315S
The AirTAC SI125X315S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 315 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. AirTAC replaced this legacy unit with the SAI125X315S, a direct replacement sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and accessories.
The SAI upgrade features a redesigned piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also introduces lock variants like the SAIL and BSAI that the original SI line lacked, while the included -S magnet supports legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X315S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X315S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X315S |
| Bore size | Ø125 mm |
| Stroke | 315 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 SAI125X315S 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 SAI125X315S 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 SI125X315S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×315 | 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 SI125X315S Is Used
Heavy Material Forming
Drives large press dies and stamping fixtures requiring high thrust, using the 6136 N push force at 0.5 MPa to form thick steel components reliably.
Pallet Diversion
Actuates heavy-duty lane diverters and sorting gates on automated packaging lines, where the 315 mm stroke provides full travel for standard pallet widths.
Replacing the Airtac SI125 Standard Cylinder SI125X315S with the SAI125X315S
To replace the SI125X315S, order the SAI125X315S. Verify your ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/2 air port, and the M27x2 rod thread. Because this is a 315 mm stroke, add external guides to prevent rod bending and side-load wear. If sizing up or down, note the 100 mm bore offers 3927 N push at 0.5 MPa, while the 160 mm bore provides 10053 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use the SAIL lock, BSAI clamp-lock, or an external pilot check valve. The -S magnet works with CS1-B/DS1-B switches; the SAI uses current AirTAC sensors.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X315S
- ✓ 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 SI125X315S FAQ
Yes, the SI125X315S is discontinued. The direct replacement is the SAI125X315S. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 315 mm stroke, force, G1/2 port, and mounting interface.
The G1/2 port feeds a 32 mm rod. Force output is 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, with a theoretical max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X315S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X315S replacement — usually within 7-8 hours.