This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X1250S, 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 SI125X1250S
The AirTAC SI125 Standard Cylinder SI125X1250S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 1250mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X1250S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke1250 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X1250S
- 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 SI125X1250S
The AirTAC SI125X1250S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 1250 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. AirTAC replaced this legacy unit with the SAI125X1250S, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, force, and port size.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line. The -S suffix means it has a piston magnet for CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X1250S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X1250S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X1250S |
| Bore size | Ø125 mm |
| Stroke | 1250 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 SAI125X1250S 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 SAI125X1250S 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 SI125X1250S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×1250 | 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 SI125X1250S Is Used
Heavy Material Transfer
Drives large product loads along extended conveyor sections using its 6136 N push force at 0.5 MPa over a 1250 mm reach.
Pallet Positioning
Shifts or indexes heavy pallets and fixtures into staging zones, utilizing the 313 kg vertical lift capacity safely.
Automated Press Feed
Feeds heavy raw materials into large hydraulic or pneumatic presses, relying on the robust 32 mm rod and 125 mm bore.
Replacing the Airtac SI125 Standard Cylinder SI125X1250S with the SAI125X1250S
To replace the SI125X1250S, order the SAI125X1250S. Verify your ISO 15552 mounting accessories (LB, FA, TC, etc.), the G1/2 air port, and the M27x2 rod thread. The 1250 mm stroke is substantial; to prevent rod bending and premature seal wear, use an external guide to absorb side loads. For sizing, neighboring bores are 100 mm (3927 N push @0.5) and 160 mm (10053 N push @0.5). This cylinder will not hold a load without air; use an external rod lock or pilot check valve, or specify the SAIL/BSAI lock variant. The magnet works with legacy CS1-B/DS1-B switches, while the SAI uses current AirTAC sensors.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X1250S
- ✓ 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 SI125X1250S FAQ
Yes, the SI125X1250S is discontinued. The direct replacement is the SAI125X1250S. It features the same ISO 15552 mounting interface, 125 mm bore, 1250 mm stroke, output force, G1/2 port, and mounting accessories, fitting directly into existing fixtures.
This double-acting cylinder has 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. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X1250S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X1250S replacement — usually within 7-8 hours.