This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X150LB, 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 SI125X150LB
The AirTAC SI125 Standard Cylinder SI125X150LB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 150mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X150LB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke150 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X150LB
- 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 SI125X150LB
The AirTAC SI125X150LB is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 150 mm stroke. Built for heavy-duty tasks, it delivers 6136 N push and 5734 N pull at 0.5 MPa, scaling to 8590 N at 0.7 MPa. The direct replacement is the SAI125X150LB, matching the ISO 15552 mounting interface, LB foot, G1/2 port and output force.
The SAI upgrade features a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this SKU lacks a magnet and cannot accept CS1-B/DS1-B sensors. For load holding on air loss, use an external rod lock or the SAIL/BSAI lock variant, as cushions only decelerate.
Airtac SI125 Standard Cylinder SI125X150LB Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X150LB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X150LB |
| Bore size | Ø125 mm |
| Stroke | 150 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 SAI125X150LB 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 SAI125X150LB 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 SI125X150LB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×150 | 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 SI125X150LB Is Used
Heavy Stamping Press
Drives large platens in metal forming, using the 6136 N push force at 0.5 MPa to shape thick gauge steel reliably.
Automated Clamp Fixture
Secures large castings during machining via the LB foot mount, providing rigid 125 mm bore clamping power.
Replacing the Airtac SI125 Standard Cylinder SI125X150LB with the SAI125X150LB
To replace the discontinued SI125X150LB, order the SAI125X150LB. Verify the ISO 15552 LB foot mounting, 150 mm stroke, G1/2 port (PT/G/NPT) and M27x2 rod thread. Because this specific SKU has no -S magnet, it cannot host position sensors; if sensing is needed, specify a magnet on the SAI order. Sizing both ways: the 125 mm bore yields 6136 N push at 0.5 MPa (max 1251 kgf at 1.0 MPa); if lower force is acceptable, an 80 mm bore provides 2513 N push. For applications requiring load holding during air loss, a plain cylinder drifts since cushions only decelerate. Specify an external pilot check valve or explore the SAIL (air-released lock) or BSAI (clamp-lock) variants. The 32 mm rod operates at 30-500 mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X150LB
- ✓ 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 SI125X150LB FAQ
Yes, the SI125X150LB is discontinued. The direct replacement is the SAI125X150LB. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 150 mm stroke, LB foot mount, G1/2 port and force ratings.
At 0.5 MPa it provides 6136 N push and 5734 N pull. Push increases to 8590 N at 0.7 MPa and 11045 N at 0.9 MPa, with 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 SAI125X150LB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X150LB replacement — usually within 7-8 hours.