This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X315STC, 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 SI125X315STC
The AirTAC SI125 Standard Cylinder SI125X315STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 315mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X315STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke315 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X315STC
- 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 SI125X315STC
The AirTAC SI125X315STC is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 315 mm stroke. It delivers 6136 N push force at 0.5 MPa, uses a G1/2 port, and features a TC trunnion mount. AirTAC replaced this EOL unit with the SAI125X315STC, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, force, and port size.
The SAI replacement introduces an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. It also adds variants the SI lacked, like the SAIL lock and BSAI clamp-lock. The -S magnet supports legacy CS1-B/DS1-B sensors, while a Viton H seal option raises operating temperature to 150 C.
Airtac SI125 Standard Cylinder SI125X315STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X315STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X315STC |
| Bore size | Ø125 mm |
| Stroke | 315 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 SAI125X315STC 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 SAI125X315STC 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 SI125X315STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×315 | 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 SI125X315STC Is Used
Heavy Press Actuation
Drives large stamping and forming presses requiring 6136 N of thrust at 0.5 MPa with robust TC trunnion mounting.
Automated Assembly Lines
Shifts heavy automotive or structural components along assembly fixtures using the ISO 15552 interface.
Replacing the Airtac SI125 Standard Cylinder SI125X315STC with the SAI125X315STC
To replace the SI125X315STC, order the SAI125X315STC. Verify your ISO 15552 TC trunnion interface, 125 mm bore, 315 mm stroke, G1/2 port, and the -S magnet for CS1-B/DS1-B switches. When sizing, note the 125 mm bore yields 6136 N push at 0.5 MPa; if you need less force, the neighboring 100 mm bore provides 3927 N. Because this is a 315 mm stroke, use an external guide to prevent rod-bending side loads. A plain cylinder drifts without live air—the cushion only decelerates—so for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X315STC
- ✓ 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 SI125X315STC FAQ
Yes, the SI125X315STC is discontinued. The direct replacement is the SAI125X315STC. It shares the same ISO 15552 TC mounting interface, 125 mm bore, 315 mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
The 125 mm bore provides 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N at 0.9 MPa, and a max force of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s. It uses a 32 mm rod, M27x2 thread, and 40 mm cushions.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X315STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X315STC replacement — usually within 7-8 hours.