This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X385S, 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 SI125X385S
The AirTAC SI125 Standard Cylinder SI125X385S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 385mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X385S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke385 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X385S
- 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 SI125X385S
The AirTAC SI125X385S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 385 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. AirTAC replaced this legacy unit with the SAI125X385S, a direct upgrade retaining the exact mounting interface, output force, and stroke.
The SAI successor features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. It also introduces lock and valve variants the SI lacked, like the SAIL and BSAI. The -S suffix means it has a piston magnet for CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X385S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X385S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X385S |
| Bore size | Ø125 mm |
| Stroke | 385 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 SAI125X385S 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 SAI125X385S 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 SI125X385S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×385 | 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 SI125X385S Is Used
Heavy Stamp Pressing
Drives large stamping dies and press tools requiring high thrust over an extended 385 mm travel distance.
Pallet Lift Stations
Actuates heavy lifting platforms in automated warehouses, moving loads up to the 313 kg vertical limit safely.
Bulk Material Diversion
Pushes heavy product bundles or pallets across main conveyor lines using the full 6136 N push capacity.
Replacing the Airtac SI125 Standard Cylinder SI125X385S with the SAI125X385S
To replace the SI125X385S, order the SAI125X385S. Verify your ISO 15552 mounting accessories (LB, FA, CA, TC), the G1/2 air port, and the M27x2 rod thread. Because the 385 mm stroke creates leverage, use an external guide 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 standard cylinder drifts without air; for load holding on pressure loss, use the SAIL lock or BSAI clamp-lock variant, or an external pilot check valve. The -S magnet supports legacy CS1-B/DS1-B switches, while the SAI uses current AirTAC sensors.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X385S
- ✓ 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 SI125X385S FAQ
Yes, the SI125X385S is discontinued. The direct replacement is the SAI125X385S. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 385 mm stroke, G1/2 port, and mounting interface, so it fits existing fixtures directly.
At 0.5 MPa it provides 6136 N push and 5734 N pull. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical max force is 1251 kgf at 1.0 MPa. Operating speed for this 125 mm bore ranges from 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X385S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X385S replacement — usually within 7-8 hours.