This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX175, 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 SI125BX175
The AirTAC SI125 Standard Cylinder SI125BX175 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 SAI125BX175, 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 → SAI125BX175
- 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 SI125BX175
The AirTAC SI125BX175 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 175 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125BX175, matching the bore, stroke, force, port and ISO 15552 mounting interface exactly. This -B variant uses a SUS304 stainless piston rod for corrosion resistance, and because it lacks the -S suffix it cannot accept a magnetic sensor.
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 absent in the SI line.
Airtac SI125 Standard Cylinder SI125BX175 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX175 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX175 |
| 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 SAI125BX175 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 SAI125BX175 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 SI125BX175
| 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 SI125BX175 Is Used
Heavy Stamping
Drives large pressing and stamping fixtures requiring high thrust, utilizing the 6136 N push force at 0.5 MPa with robust SUS304 rod corrosion resistance.
Pallet Diverting
Actuates heavy-duty pallet diverters and lifting gates in high-throughput logistics hubs, moving loads safely within the 3682 N working limit.
Mold Clamping
Secures heavy injection molds and industrial platens, where the 125 mm bore provides the clamping mass needed for stable manufacturing processes.
Replacing the Airtac SI125 Standard Cylinder SI125BX175 with the SAI125BX175
To replace the SI125BX175, order the SAI125BX175. Verify the ISO 15552 mounting interface, the 125 mm bore, 175 mm stroke, G1/2 port (PT/G/NPT threads), and your mounting accessory. Because this SKU lacks a magnet (-S), it cannot take a sensor; the legacy SI used CS1-B/DS1-B switches, while the SAI uses current AirTAC switches. Sizing both ways: a 100 mm bore gives 3927 N push at 0.5 MPa, while a 160 mm bore gives 10053 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. Stroke is under 300 mm so rod bending is minimal, but always guide the load.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX175
- ✓ 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 SI125BX175 FAQ
Yes, the SI125BX175 is discontinued. The direct replacement is the SAI125BX175. It shares the same ISO 15552 mounting interface, 125 mm bore, 175 mm stroke, output force, G1/2 port, and SUS304 stainless rod, fitting existing fixtures perfectly.
It has a G1/2 port. The force 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 max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX175
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