This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X850, 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 SI125X850
The AirTAC SI125 Standard Cylinder SI125X850 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 850mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X850, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke850 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X850
- 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 SI125X850
The AirTAC SI125X850 is a discontinued double-acting ISO 15552 profile cylinder with an 850 mm stroke. Delivering 6136 N push force at 0.5 MPa, it uses a G1/2 port and M27x2 rod thread. The direct replacement is the SAI125X850, matching the exact ISO 15552 mounting interface, bore, stroke, force, and port size for existing fixtures.
The SAI125X850 upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This SKU lacks a magnet so it cannot take a sensor. For load holding, the cushion only decelerates; use an external rod lock or the SAIL/BSAI lock variants.
Airtac SI125 Standard Cylinder SI125X850 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X850 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X850 |
| Bore size | Ø125 mm |
| Stroke | 850 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 SAI125X850 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 SAI125X850 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 SI125X850
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×850 | 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 SI125X850 Is Used
Heavy Material Transfer
Drives large pallets or heavy fabricated components along assembly lines using its 6136 N push force at 0.5 MPa over an 850 mm travel distance.
Pallet Positioning
Indexes loaded pallets into wrapping or strapping stations, requiring the robust 125 mm bore and G1/2 port capacity for high thrust.
Large Press Ejection
Ejects formed parts from heavy industrial presses, utilizing the 850 mm stroke to clear the machine bed while managing substantial side loads.
Replacing the Airtac SI125 Standard Cylinder SI125X850 with the SAI125X850
To replace the SI125X850, order the SAI125X850. Confirm the ISO 15552 mounting accessory (LB, FA, CA, TC), the G1/2 port, and the M27x2 rod thread. This non-magnet SKU cannot accept a CS1-B/DS1-B sensor; if sensing is needed, specify an SAI with the -S magnet option. The 850 mm stroke exceeds 300 mm, so use an external guide to prevent rod bending and side loads. Sizing both ways: the 125 mm bore yields 6136 N push at 0.5 MPa (8590 N at 0.7 MPa), while a 100 mm bore provides 3927 N at 0.5 MPa. For dead-load holding, note that a plain cylinder drifts on air loss; add a pilot check valve or select the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X850
- ✓ 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 SI125X850 FAQ
Yes, the AirTAC SI125X850 is discontinued. The direct replacement is the SAI125X850. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 850 mm stroke, 6136 N force, G1/2 port, and mounting interface.
This double-acting cylinder delivers 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. Operating speed is 30-500 mm/s. It uses a G1/2 port and M27x2 rod thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X850
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X850 replacement — usually within 7-8 hours.