This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X370, 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 SI125X370
The AirTAC SI125 Standard Cylinder SI125X370 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 370mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X370, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke370 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X370
- 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 SI125X370
The AirTAC SI125X370 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 370 mm stroke. It delivers 6136 N push and 5734 N pull at 0.5 MPa, operating with a G1/2 port. AirTAC replaced this legacy unit with the SAI125X370, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, force and port.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this SKU lacks the -S magnet, so it cannot accept CS1-B/DS1-B sensors. The SAI family also introduces SAIL and BSAI lock variants absent from the SI line.
Airtac SI125 Standard Cylinder SI125X370 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X370 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X370 |
| Bore size | Ø125 mm |
| Stroke | 370 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 SAI125X370 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 SAI125X370 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 SI125X370
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×370 | 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 SI125X370 Is Used
Heavy Stamping Press
Drives large platens and stamping dies requiring high thrust, utilizing the 6136 N push force at 0.5 MPa to form thick metal components reliably.
Pallet Actuated Gate
Indexes heavy loaded pallets on conveyor lines, where the 370 mm stroke provides the full reach needed to open wide diversion gates safely.
Large Mold Clamping
Secures substantial injection molds during setup cycles, depending on the 125 mm bore's robust pull force to hold heavy tooling firmly in place.
Replacing the Airtac SI125 Standard Cylinder SI125X370 with the SAI125X370
To replace the SI125X370, order the SAI125X370 direct equivalent. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/2 port thread (PT, G or NPT), and the M27x2 rod thread. Since this specific SKU has no -S magnet, it cannot support position sensing; if switches are needed, select an SAI125X370S and use current AirTAC sensors. For sizing, a 125 mm bore yields 6136 N at 0.5 MPa; dropping to a 100 mm bore reduces force to 3927 N, while increasing pressure to 0.7 MPa provides 8590 N. A standard cylinder drifts without live air—the cushion only decelerates—so use a SAIL or BSAI lock variant, or external pilot check valve, to hold loads. With the 370 mm stroke, use external guides to prevent rod bending and side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X370
- ✓ 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 SI125X370 FAQ
Yes, the SI125X370 is discontinued. The direct replacement is the AirTAC SAI125X370. It shares the identical ISO 15552 mounting interface, 125 mm bore, 370 mm stroke, output force, and G1/2 port, fitting directly into existing fixtures without modifications.
The 125 mm bore features a G1/2 air port and M27x2 rod thread. It generates 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 maximum of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X370
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X370 replacement — usually within 7-8 hours.