This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X250SCA, 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 SI125X250SCA
The AirTAC SI125 Standard Cylinder SI125X250SCA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 250mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X250SCA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke250 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X250SCA
- 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 SI125X250SCA
The AirTAC SI125X250SCA is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 250 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. AirTAC replaced this legacy unit with the SAI125X250SCA, a direct sharing the exact ISO 15552 mounting interface, CA clevis mount, stroke and output force.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors, while the SAI uses current switches.
Airtac SI125 Standard Cylinder SI125X250SCA Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X250SCA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X250SCA |
| Bore size | Ø125 mm |
| Stroke | 250 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 SAI125X250SCA 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 SAI125X250SCA 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 SI125X250SCA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×250 | 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 SI125X250SCA Is Used
Heavy Press Clamping
Secures large metal castings in machining centers, utilizing the 6136 N push force to hold components rigidly against cutting loads.
Pallet Lift Gates
Actuates heavy loading dock gates where the 313 kg vertical lift capacity and CA clevis mount handle substantial off-center payloads smoothly.
Bulk Material Diversion
Drives large-scale package diverters on high-throughput sorting lines, moving heavy goods with a 250 mm stroke at 30-500 mm/s.
Replacing the Airtac SI125 Standard Cylinder SI125X250SCA with the SAI125X250SCA
To replace the SI125X250SCA, order the SAI125X250SCA. Confirm the ISO 15552 interface, 125 mm bore, 250 mm stroke, G1/2 port, CA clevis mount and -S magnet. The direct fits existing fixtures perfectly. If sizing up or down, neighbouring bores are 100 mm and 160 mm; at 0.5 MPa the 100 mm yields 3927 N push, while the 160 mm yields 10053 N. Note that a plain cylinder drifts on air loss as the cushion only decelerates; for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. Rod material options include carbon steel, SUS420J2 (A) or SUS304 (B).
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X250SCA
- ✓ 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 SI125X250SCA FAQ
Yes, the SI125X250SCA is discontinued. The direct replacement is the SAI125X250SCA. It shares the identical ISO 15552 mounting interface, 125 mm bore, 250 mm stroke, G1/2 port and CA clevis mount, fitting existing fixtures directly.
This double-acting cylinder uses a G1/2 port. It generates 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N 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 SAI125X250SCA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X250SCA replacement — usually within 7-8 hours.