This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X185STC, 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 SI125X185STC
The AirTAC SI125 Standard Cylinder SI125X185STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 185mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X185STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke185 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X185STC
- 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 SI125X185STC
The AirTAC SI125X185STC is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 185mm stroke. It delivers 6136N push force at 0.5MPa through a G1/2 port. The direct replacement is the SAI125X185STC, which retains the same interface, force, and TC trunnion mount.
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, SAIF, and BSAI lock variants the SI lacked. This -S model has a piston magnet for CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X185STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X185STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X185STC |
| Bore size | Ø125 mm |
| Stroke | 185 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 SAI125X185STC 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 SAI125X185STC 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 SI125X185STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×185 | 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 SI125X185STC Is Used
Heavy Press Operations
Drives high-tonnage stamping and forming presses where the 6136N push force at 0.5MPa is required for consistent metal deformation.
Bulk Material Diversion
Pushes heavy product bundles or pallets on packaging lines, utilizing the 32mm rod and M27x2 thread for rigid load transfer.
Replacing the Airtac SI125 Standard Cylinder SI125X185STC with the SAI125X185STC
To replace the SI125X185STC, order the SAI125X185STC. Verify the ISO 15552 TC trunnion mounting, 125mm bore, 185mm stroke, G1/2 port, and the -S magnet for current AirTAC switches. Sizing both ways: a 100mm bore yields 3927N [email protected], while a 160mm bore yields 10053N. Note that a plain cylinder drifts without live air; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant. At 185mm stroke, side-load is minimal, but always guide the rod to prevent bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X185STC
- ✓ 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 SI125X185STC FAQ
Yes, the SI125X185STC is discontinued. The direct replacement is the SAI125X185STC. It is dimensionally interchangeable per ISO 15552, retaining the same bore, stroke, force, G1/2 port, and TC mounting interface.
This double-acting cylinder uses a G1/2 port. Force ratings are: 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical max of 1251kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X185STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X185STC replacement — usually within 7-8 hours.