This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X50N, 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 SI125X50N
The AirTAC SI125 Standard Cylinder SI125X50N is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 50mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X50N, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke50 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X50N
- 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 SI125X50N
The AirTAC SI125X50N is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 50 mm stroke. Delivering 6136 N push force at 0.5 MPa, it features a G1/2 port, M27x2 rod thread, and NBR seals rated for -20 to +70 C. As this SKU lacks a magnet (-S), it cannot accept position sensors.
The direct replacement is the SAI125X50N, retaining the exact ISO 15552 mounting interface, bore, stroke, and port. The SAI upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life.
Airtac SI125 Standard Cylinder SI125X50N Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X50N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X50N |
| Bore size | Ø125 mm |
| Stroke | 50 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 SAI125X50N 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 SAI125X50N 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 SI125X50N
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×50 | 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 SI125X50N Is Used
Heavy Stamping
Provides the robust 6136 N push force needed to actuate large presses and form heavy gauge sheet metal.
Pallet Handling
Drives heavy-duty diverters and lifts in automated warehouses, moving loaded pallets with a 313 kg vertical lift margin.
Injection Molding
Secures large molds and clamps industrial injection molding machinery safely under high pressure.
Replacing the Airtac SI125 Standard Cylinder SI125X50N with the SAI125X50N
To replace the SI125X50N, order the SAI125X50N. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 50 mm stroke, G1/2 port, and NBR seals. Because this specific SKU has no magnet, it cannot support legacy CS1-B/DS1-B sensors; order an -S variant if sensing is required. If sizing down, a 100 mm bore yields 3927 N push at 0.5 MPa. If sizing up, a 160 mm bore provides 10053 N. Note that a plain cylinder drifts on air loss; for load holding, use the SAIL or BSAI lock variant, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X50N
- ✓ 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 SI125X50N FAQ
Yes, the SI125X50N is discontinued. The direct replacement is the SAI125X50N. It shares the identical ISO 15552 mounting interface, 125 mm bore, 50 mm stroke, force, and G1/2 port, fitting existing fixtures perfectly.
This double-acting cylinder features a G1/2 port. It 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. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X50N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X50N replacement — usually within 7-8 hours.