This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X300SH, 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 SI125X300SH
The AirTAC SI125 Standard Cylinder SI125X300SH is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 300mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X300SH, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke300 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X300SH
- 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 SI125X300SH
The AirTAC SI125X300SH is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore, 300mm stroke, and a G1/2 port. Delivering 6136 N of push force at 0.5 MPa, it is replaced by the SAI125X300SH. This direct successor shares identical mounting, output, and dimensions, fitting existing fixtures perfectly.
The SAI upgrade introduces a two-piece Y-shaped piston seal for low start-up pressure and extended life. The -H suffix specifies Viton FKM seals for 0-150 C heat, while the -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X300SH Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X300SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X300SH |
| Bore size | Ø125 mm |
| Stroke | 300 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 SAI125X300SH 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 SAI125X300SH 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 SI125X300SH
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×300 | 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 SI125X300SH Is Used
Heavy Press Clamping
Secures large metal castings during machining, utilizing the 6136 N push force at 0.5 MPa to hold components rigidly under tool vibration.
Pallet Lift Gates
Actuates heavy-duty loading dock gates, where the 300mm stroke provides the travel needed to clear tall palletized freight safely.
High-Tact Forming
Drives resin or composite molding presses in heated zones, relying on the Viton H seals to withstand continuous 150 C operating temperatures.
Replacing the Airtac SI125 Standard Cylinder SI125X300SH with the SAI125X300SH
To replace the SI125X300SH, order the SAI125X300SH. Confirm the ISO 15552 mounting interface, G1/2 port, M27x2 rod thread, and your specific mounting accessory (LB, FA, TC, etc.). The SAI family also adds the SAIL lock and BSAI clamp-lock variants absent from the SI line; note that a plain cylinder drifts on air loss, so use these or external pilot check valves for load holding. If sizing up or down, neighbouring bores (100/160mm) alter the 6136 N @0.5 MPa force. Because the 300mm stroke is long, prevent rod bending by guiding the load externally to avoid side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X300SH
- ✓ 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 SI125X300SH FAQ
Yes, the SI125X300SH is discontinued. The direct replacement is the SAI125X300SH. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 300mm stroke, G1/2 port, and mounting interface, so it drops directly into existing fixtures.
This double-acting cylinder 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, with a 40mm adjustable air cushion at both ends.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X300SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X300SH replacement — usually within 7-8 hours.