This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X150STC, 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 SI125X150STC
The AirTAC SI125 Standard Cylinder SI125X150STC 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 SAI125X150STC, 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 → SAI125X150STC
- 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 SI125X150STC
The AirTAC SI125X150STC is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 150 mm stroke, delivering 6136 N push force at 0.5 MPa. It features a TC trunnion mount, G1/2 port, and a piston magnet for legacy CS1-B/DS1-B sensors. AirTAC replaced this legacy unit with the SAI125X150STC, a direct sharing the same ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade introduces a refined piston seal with two Y-shaped one-way elements for lower start-up pressure and extended lifespan. Note that a standard cylinder drifts without live air; for load holding, explore the SAIL lock or BSAI clamp-lock variants.
Airtac SI125 Standard Cylinder SI125X150STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X150STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X150STC |
| 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 SAI125X150STC 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 SAI125X150STC 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 SI125X150STC
| 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 SI125X150STC Is Used
Heavy Stamping Press
Drives heavy tooling beds in automated stamping lines, utilizing the 6136 N push force at 0.5 MPa to form thick gauge metal components reliably.
Pallet Actuation Gate
Shifts robust diverter gates on high-capacity pallet conveyors, where the TC trunnion mount absorbs lateral stress during heavy load redirection.
Injection Mold Ejector
Provides steady ejection force for large injection molds, relying on the 40 mm adjustable air cushions to decelerate the 32 mm rod smoothly at stroke ends.
Replacing the Airtac SI125 Standard Cylinder SI125X150STC with the SAI125X150STC
To replace the SI125X150STC, order the SAI125X150STC. Verify your ISO 15552 TC trunnion mounting dimensions, 150 mm stroke, G1/2 port threads (PT/G/NPT), and the -S magnet requirement for current AirTAC switches. Sizing context: this 125 mm bore yields 6136 N push at 0.5 MPa; if less force is acceptable, a 100 mm bore provides 3927 N. For load holding on air loss, the cushion only decelerates and cannot brake the piston—specify an external pilot check valve or the SAIL/BSAI lock variants. Operating speed is 30-500 mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X150STC
- ✓ 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 SI125X150STC FAQ
Yes, the SI125X150STC is discontinued. The direct replacement is the SAI125X150STC. It shares the identical ISO 15552 mounting interface, 125 mm bore, 150 mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly while upgrading the piston seal.
This 125 mm bore cylinder uses a G1/2 air port. At 0.5 MPa it provides 6136 N push and 5734 pull force. At 0.7 MPa push is 8590 N, and 11045 N at 0.9 MPa. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X150STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X150STC replacement — usually within 7-8 hours.