This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X375S, 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 SI125X375S
The AirTAC SI125 Standard Cylinder SI125X375S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 375mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X375S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke375 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X375S
- 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 SI125X375S
The AirTAC SI125X375S is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore and 375mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. AirTAC replaced this legacy unit with the SAI125X375S, a direct upgrade retaining the exact interface, M27x2 thread, and 40mm cushions.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure. The family adds SAIL and BSAI lock variants the SI lacked. This -S SKU uses CS1-B/DS1-B sensors; Viton H raises temps to 150C.
Airtac SI125 Standard Cylinder SI125X375S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X375S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X375S |
| Bore size | Ø125 mm |
| Stroke | 375 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 SAI125X375S 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 SAI125X375S 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 SI125X375S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×375 | 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 SI125X375S Is Used
Heavy Press Clamping
Secures large steel plates in a machining fixture, using the 6136N thrust to hold components firmly during milling operations.
Pallet Lift Stations
Raises loaded pallets via a 375mm stroke, safely moving loads up to the 313kg vertical lift limit through the transfer conveyor.
Automated Forming Ejector
Ejects heavy pressed metal parts from hydraulic presses, absorbing end-of-stroke kinetic energy via the 40mm adjustable cushions.
Replacing the Airtac SI125 Standard Cylinder SI125X375S with the SAI125X375S
To replace the SI125X375S, order the SAI125X375S. Verify the ISO 15552 mounting accessory (LB, FA, CA, TC), the G1/2 port, and the -S magnet for CS1-B/DS1-B switches. Neighbouring bores are 100mm (3927N [email protected]) and 160mm (10053N [email protected]). Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock or the SAIL/BSAI variant. At 375mm stroke, use external guides to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X375S
- ✓ 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 SI125X375S FAQ
Yes, the SI125X375S is discontinued. The direct replacement is the SAI125X375S. It is dimensionally interchangeable per ISO 15552, matching the 125mm bore, 375mm stroke, G1/2 port, and mounting fixtures.
At 0.5MPa it pushes 6136N and pulls 5734N. At 0.7MPa push is 8590N, and 11045N at 0.9MPa. The theoretical max is 1251kgf at 1.0MPa. Operating speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X375S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X375S replacement — usually within 7-8 hours.