This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX850, 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 SI125BX850
The AirTAC SI125 Standard Cylinder SI125BX850 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 SAI125BX850, 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 → SAI125BX850
- 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 SI125BX850
The AirTAC SI125BX850 is a discontinued double-acting ISO 15552 profile cylinder with an 850 mm stroke and a SUS304 stainless steel rod. Generating 6136 N push force at 0.5 MPa, it is superseded by the SAI125BX850 direct replacement. This upgrade shares the exact G1/2 port, M27x2 thread, and ISO 15552 mounting interface, but adds an upgraded two Y-shaped one-way piston seal for lower start-up pressure.
Because this SKU lacks a magnet, it cannot accept a position switch. The SAI family also introduces SAIL and BSAI lock variants absent in the legacy SI line.
Airtac SI125 Standard Cylinder SI125BX850 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX850 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX850 |
| 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 SAI125BX850 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 SAI125BX850 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 SI125BX850
| 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 SI125BX850 Is Used
Heavy Material Ejection
Provides the 6136 N push force needed to eject heavy pallets or metal blanks from a production line over the 850 mm travel distance.
Pallet Positioning
Shifts loaded pallets laterally between conveyors where the SUS304 rod resists moisture and the long stroke accommodates wide transfer stations.
Large Press Feeding
Feeds large sheet metal blanks into a press, requiring external guides to manage the 850 mm stroke and prevent rod bending under heavy loads.
Replacing the Airtac SI125 Standard Cylinder SI125BX850 with the SAI125BX850
To replace the SI125BX850, order the SAI125BX850. Verify the ISO 15552 mounting interface, 125 mm bore, 850 mm stroke, G1/2 port, and SUS304 stainless rod. With no -S magnet, this cylinder cannot support sensing; if detection is needed, select a magnet-equipped SAI. Operating speed is 30-500 mm/s. For sizing, the 6136 N push at 0.5 MPa yields a 3682 N safe load; if more force is needed, consider the 160 mm bore. Note that an 850 mm stroke demands external guides to prevent rod bending under side loads. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX850
- ✓ 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 SI125BX850 FAQ
Yes, the AirTAC SI125BX850 is discontinued. The direct replacement is the SAI125BX850. It shares the same ISO 15552 mounting interface, 125 mm bore, 850 mm stroke, G1/2 port, and output force, fitting existing fixtures perfectly.
It features a G1/2 port and M27x2 rod thread. 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 maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX850
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX850 replacement — usually within 7-8 hours.