This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X125STC, 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 SI125X125STC
The AirTAC SI125 Standard Cylinder SI125X125STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 125mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X125STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke125 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X125STC
- 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 SI125X125STC
The AirTAC SI125X125STC is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore and 125 mm stroke. It delivers 6136 N push force at 0.5 MPa and uses a G1/2 air port with a TC trunnion mount. AirTAC replaced this legacy unit with the SAI125X125STC, a direct replacement sharing the exact same ISO 15552 mounting interface, output force, and port size.
The SAI upgrade introduces a refined piston seal utilizing two Y-shaped one-way elements for lower start-up pressure and extended life. Beyond the standard carbon steel rod, original seal and rod material options like SUS304 (B) and Viton H (for 0-150 C heat) were available. Because this SKU includes the -S magnet, it supports legacy CS1-B/DS1-B sensors, whereas the SAI family uses current AirTAC switches.
Airtac SI125 Standard Cylinder SI125X125STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X125STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X125STC |
| Bore size | Ø125 mm |
| Stroke | 125 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 SAI125X125STC 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 SAI125X125STC 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 SI125X125STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×125 | 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 SI125X125STC Is Used
Heavy Stamping Press
Drives heavy tooling assemblies in automated stamping lines, utilizing the 6136 N push force at 0.5 MPa to form thick gauge metal components reliably.
Large Component Clamping
Secures oversized machinery housings during machining operations via the rigid TC trunnion mount, handling high side-load stresses during the 125 mm stroke.
Replacing the Airtac SI125 Standard Cylinder SI125X125STC with the SAI125X125STC
To replace the discontinued SI125X125STC, order the SAI125X125STC. Verify your existing fixture accommodates the ISO 15552 TC trunnion mount, 125 mm bore, 125 mm stroke, and G1/2 port. If you need to scale up or down, neighboring bores are 100 mm and 160 mm; at 0.5 MPa, this 125 mm bore provides 6136 N push and 5734 N pull. A plain pneumatic cylinder cannot hold a load if air pressure drops—the adjustable 40 mm air cushions only decelerate the piston near stroke ends. For secure load holding, consider an external pilot check valve, a rod lock, or the SAIL (air-released lock) and BSAI (clamp-lock) variants from the SAI family. The SAIF variant with a built-in 4M valve is only offered in bores 32-100.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X125STC
- ✓ 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 SI125X125STC FAQ
Yes, the AirTAC SI125X125STC is discontinued and end-of-life. The direct replacement is the SAI125X125STC. It shares the identical ISO 15552 mounting interface, 125 mm bore, 125 mm stroke, G1/2 port, and output force, so it fits directly into your existing TC trunnion fixtures.
This double-acting 125 mm bore cylinder operates at 30-500 mm/s. The thrust ratings are: 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 force of 1251 kgf at 1.0 MPa. It features a G1/2 air port and a 40 mm adjustable cushion at both ends.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X125STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X125STC replacement — usually within 7-8 hours.