This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X505S, 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 SI125X505S
The AirTAC SI125 Standard Cylinder SI125X505S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 505mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X505S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke505 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X505S
- 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 SI125X505S
The AirTAC SI125X505S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 505 mm stroke. It delivers 6136 N push and 5734 N pull at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125X505S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also introduces lock and valve variants the SI lacked, and the -S magnet on this unit works with legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X505S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X505S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X505S |
| Bore size | Ø125 mm |
| Stroke | 505 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 SAI125X505S 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 SAI125X505S 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 SI125X505S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×505 | 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 SI125X505S Is Used
Heavy Press Clamping
Secures large metal castings in machining fixtures, utilizing the 6136 N push force at 0.5 MPa to hold components rigidly against cutting loads.
Bulk Material Diversion
Actuates heavy-duty diverter gates on conveyor lines, using the 505 mm stroke to redirect large volumes of aggregate or packaged goods.
Replacing the Airtac SI125 Standard Cylinder SI125X505S with the SAI125X505S
To replace the SI125X505S, order the SAI125X505S. Confirm the ISO 15552 mounting interface, the G1/2 port, your PT/G/NPT thread standard, and the mounting accessory (LB, FA, TC, etc.). The -S suffix means a piston magnet is present for CS1-B/DS1-B switches; the SAI replacement uses current AirTAC switches. If you need more force, the neighboring 160 mm bore offers 10053 N push at 0.5 MPa; if less is acceptable, the 100 mm bore provides 3927 N. Remember, a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. Because the 505 mm stroke is long, use external guides to prevent rod bending and side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X505S
- ✓ 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 SI125X505S FAQ
Yes, the SI125X505S is discontinued. The direct replacement is the AirTAC SAI125X505S. It features the same ISO 15552 mounting interface, 125 mm bore, 505 mm stroke, output force, and G1/2 port, fitting directly into existing fixtures.
This double-acting cylinder operates at 0.15-1.0 MPa (proof 1.5 MPa) with a speed of 30-500 mm/s. 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 theoretical max of 1251 kgf at 1.0 MPa. It has a 32 mm rod, M27x2 thread, and 40 mm cushions.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X505S
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