This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX175STC, 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 SI125BX175STC
The AirTAC SI125 Standard Cylinder SI125BX175STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 175mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX175STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke175 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX175STC
- 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 SI125BX175STC
The AirTAC SI125BX175STC is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore, 175mm stroke, SUS304 stainless piston rod, and a TC trunnion mount. Delivering 6136N push force at 0.5MPa, it is replaced by the direct replacement SAI125BX175STC. This SAI model shares the exact interface, G1/2 port, and 1251kgf max force, fitting existing fixtures seamlessly.
The SAI upgrade utilizes two Y-shaped one-way piston seals for low start-up pressure and long life. The SAI family adds SAIL and BSAI lock variants the SI lacked. This -S SKU supports legacy CS1-B/DS1-B sensors, while Viton H seals raise temps to 150C.
Airtac SI125 Standard Cylinder SI125BX175STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX175STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX175STC |
| Bore size | Ø125 mm |
| Stroke | 175 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 SAI125BX175STC 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 SAI125BX175STC 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 SI125BX175STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×175 | 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 SI125BX175STC Is Used
Heavy-Duty Pressing
Applies 6136N at 0.5MPa for seating heavy components and forming operations, utilizing the SUS304 rod in corrosive environments.
Bulk Material Diversion
Pushes heavy product flows at 30-500mm/s, relying on the 40mm adjustable air cushions to decelerate the 32mm rod at stroke ends.
Replacing the Airtac SI125 Standard Cylinder SI125BX175STC with the SAI125BX175STC
To replace the SI125BX175STC, order the SAI125BX175STC. Verify the ISO 15552 TC trunnion mounting, 175mm stroke, G1/2 port, and the -S magnet for CS1-B/DS1-B sensors. The -B SUS304 rod is retained. Sizing both ways: a 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore yields 10053N. At 0.7MPa this 125mm bore pushes 8590N. 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.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX175STC
- ✓ 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 SI125BX175STC FAQ
Yes, the AirTAC SI125BX175STC is discontinued. The direct replacement is the SAI125BX175STC. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 175mm stroke, G1/2 port, TC mount, and output force.
It features a G1/2 air port. At 0.5MPa it provides 6136N push and 5734N pull force. At 0.7MPa it pushes 8590N, and 11045N at 0.9MPa. The theoretical maximum force is 1251kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX175STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX175STC replacement — usually within 7-8 hours.