This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X900N, 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 SI125X900N
The AirTAC SI125 Standard Cylinder SI125X900N is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 900mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X900N, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke900 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X900N
- 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 SI125X900N
The AirTAC SI125X900N is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 900 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125X900N, which shares identical mounting, force, and porting for seamless fixture integration.
This NBR-sealed unit lacks a magnet and cannot accept sensors. The SAI upgrade features two Y-shaped piston seals for low start-up pressure. Note that standard cylinders drift without air; use a SAIL lock or external check valve for holding.
Airtac SI125 Standard Cylinder SI125X900N Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X900N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X900N |
| Bore size | Ø125 mm |
| Stroke | 900 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 SAI125X900N 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 SAI125X900N 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 SI125X900N
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×900 | 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 SI125X900N Is Used
Heavy Material Handling
Drives large pneumatic presses and heavy material lifts requiring robust 6136 N push force at 0.5 MPa over extended distances.
Automated Assembly Lines
Actuates heavy-duty workpiece pallets and transfer arms across 900 mm strokes, relying on external guides to prevent rod bending.
Pallet Positioning Systems
Indexes loaded pallets in distribution hubs, utilizing the 125 mm bore capacity to move substantial weights safely.
Replacing the Airtac SI125 Standard Cylinder SI125X900N with the SAI125X900N
To replace the discontinued SI125X900N, order the SAI125X900N. Confirm the ISO 15552 interface, 900 mm stroke, G1/2 port (PT/G/NPT), and mounting accessories. Because this is a no-S SKU, it cannot accept a magnetic switch; if sensing is needed, select an SAI with a magnet. At 0.5 MPa, the 125 mm bore yields 6136 N push and 5734 N pull; if undersizing, a 100 mm bore provides 3927 N. For a 900 mm stroke, external guides are critical to prevent rod bending and side-load damage. This plain cylinder drifts on air loss; for load holding, specify the SAIL lock variant, BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X900N
- ✓ 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 SI125X900N FAQ
Yes, the SI125X900N is discontinued. The direct replacement is the SAI125X900N. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 900 mm stroke, force, G1/2 port, and mounting interface.
This double-acting cylinder operates at 0.15-1.0 MPa (proof 1.5 MPa) with a speed of 30-500 mm/s. It features a G1/2 port and M27x2 rod thread. 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, and a maximum theoretical force of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X900N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X900N replacement — usually within 7-8 hours.