This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X210STC, 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 SI125X210STC
The AirTAC SI125 Standard Cylinder SI125X210STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 210mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X210STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke210 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X210STC
- 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 SI125X210STC
The AirTAC SI125X210STC is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 210mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. The direct replacement is the SAI125X210STC, matching the exact TC trunnion mount, M27x2 rod thread, and output force.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL and BSAI lock variants the SI lacked.
Airtac SI125 Standard Cylinder SI125X210STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X210STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X210STC |
| Bore size | Ø125 mm |
| Stroke | 210 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 SAI125X210STC 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 SAI125X210STC 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 SI125X210STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×210 | 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 SI125X210STC Is Used
Heavy Press Clamping
Generates 8590N at 0.7MPa to secure large steel plates during machining or welding operations.
Pallet Lift Gates
Provides the robust push and pull force needed to raise and lower loaded conveyor transfer gates.
Industrial Door Actuation
Drives large automated facility doors, utilizing the TC trunnion mount to handle pivoting loads.
Replacing the Airtac SI125 Standard Cylinder SI125X210STC with the SAI125X210STC
To replace the SI125X210STC, order the SAI125X210STC. Verify the ISO 15552 TC trunnion interface, 125mm bore, 210mm stroke, G1/2 port, and the -S magnet for CS1-B/DS1-B switches (the SAI uses current AirTAC switches). If sizing up or down, neighbouring bores (100mm / 160mm) change the 0.5MPa push force (3927N / 10053N). A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 210mm stroke, rod-bending side loads are low, but always guide the payload to prevent seal wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X210STC
- ✓ 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 SI125X210STC FAQ
Yes, the SI125X210STC is discontinued. The direct replacement is the SAI125X210STC. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 210mm stroke, G1/2 port, TC mount, and force ratings.
The G1/2 port bore delivers 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N at 0.9MPa, and a theoretical max of 1251kgf at 1.0MPa. It operates at 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X210STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X210STC replacement — usually within 7-8 hours.